kernel: Activate KERNEL_MIPS_FP_SUPPORT for pistachio target

The pistachio target uses a MIPS CPU with FPU and OpenWrt uses a
toolchain with hard FPU support. MIPS FPU support needs the FPU
emulation code in the kernel.

Fixes: ac5671f4 ("kernel: remove obsolete kernel version switches for 4.19")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

config/Config-kernel.in

@@ -46,6 +46,7 @@ config KERNEL_DEBUG_FS
 
 config KERNEL_MIPS_FP_SUPPORT
 	bool
+	default y if TARGET_pistachio
 
 config KERNEL_ARM_PMU
 	bool