kernel: backport pending fix to select CPU_MIPS64

The CPU_MIPS64 and CPU_MIPS32 variables are supposed to be able to
distinguish broadly between 64-bit and 32-bit MIPS CPUs. However, they
weren't selected by the specialty CPUs, Octeon and Loongson, which meant
it was possible to hit a weird state of:

   MIPS=y, CONFIG_64BIT=y, CPU_MIPS64=n

This commit rectifies the issue by having CPU_MIPS64 be selected when
the missing Octeon or Loongson models are selected.

In particular, this affects our octeonplus target.

It has been posted to LKML here:
https://lore.kernel.org/linux-mips/20210227122605.2680138-1-Jason@zx2c4.com/



Cc: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>
Cc: David Bauer <mail@david-bauer.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

target/linux/generic/pending-5.10/103-MIPS-select-CPU_MIPS64-for-remaining-MIPS64-CPUs.patch

+From 6523061868212473f63812a0c477a161742bed42 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Sat, 27 Feb 2021 13:20:24 +0100
+Subject: [PATCH] MIPS: select CPU_MIPS64 for remaining MIPS64 CPUs
+
+The CPU_MIPS64 and CPU_MIPS32 variables are supposed to be able to
+distinguish broadly between 64-bit and 32-bit MIPS CPUs. However, they
+weren't selected by the specialty CPUs, Octeon and Loongson, which meant
+it was possible to hit a weird state of:
+
+    MIPS=y, CONFIG_64BIT=y, CPU_MIPS64=n
+
+This commit rectifies the issue by having CPU_MIPS64 be selected when
+the missing Octeon or Loongson models are selected.
+
+Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
+Cc: Ralf Baechle <ralf@linux-mips.org>
+Cc: George Cherian <gcherian@marvell.com>
+Cc: Huacai Chen <chenhuacai@kernel.org>
+Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ arch/mips/Kconfig | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/mips/Kconfig
++++ b/arch/mips/Kconfig
+@@ -2075,7 +2075,7 @@ config CPU_MIPS32
+ config CPU_MIPS64
+ 	bool
+ 	default y if CPU_MIPS64_R1 || CPU_MIPS64_R2 || CPU_MIPS64_R5 || \
+-		     CPU_MIPS64_R6
++		     CPU_MIPS64_R6 || CPU_LOONGSON64 || CPU_CAVIUM_OCTEON
+ 
+ #
+ # These indicate the revision of the architecture

target/linux/generic/pending-5.4/103-MIPS-select-CPU_MIPS64-for-remaining-MIPS64-CPUs.patch

+From 31ca877744d95713e4925de542e1c686ab08a542 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Sat, 27 Feb 2021 13:20:24 +0100
+Subject: [PATCH] MIPS: select CPU_MIPS64 for remaining MIPS64 CPUs
+
+The CPU_MIPS64 and CPU_MIPS32 variables are supposed to be able to
+distinguish broadly between 64-bit and 32-bit MIPS CPUs. However, they
+weren't selected by the specialty CPUs, Octeon and Loongson, which meant
+it was possible to hit a weird state of:
+
+    MIPS=y, CONFIG_64BIT=y, CPU_MIPS64=n
+
+This commit rectifies the issue by having CPU_MIPS64 be selected when
+the missing Octeon or Loongson models are selected.
+
+Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
+Cc: Ralf Baechle <ralf@linux-mips.org>
+Cc: George Cherian <gcherian@marvell.com>
+Cc: Huacai Chen <chenhuacai@kernel.org>
+Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ arch/mips/Kconfig | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/arch/mips/Kconfig
++++ b/arch/mips/Kconfig
+@@ -2036,7 +2036,8 @@ config CPU_MIPS32
+ 
+ config CPU_MIPS64
+ 	bool
+-	default y if CPU_MIPS64_R1 || CPU_MIPS64_R2 || CPU_MIPS64_R6
++	default y if CPU_MIPS64_R1 || CPU_MIPS64_R2 || CPU_MIPS64_R6 || \
++		     CPU_LOONGSON64 || CPU_CAVIUM_OCTEON
+ 
+ #
+ # These indicate the revision of the architecture