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>