MIPS: Loongson32: Revert ISA level to MIPS32R2

GS232 core have implemented all necessary mips32r2 instructions.
Serval missing FP instructions can be emulated by kernel.

The issue of di instruction have been solved.
Thus we revert the ISA level back to MIPS32R2.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: keguang.zhang@gmail.com

arch/mips/Kconfig

@@ -1864,7 +1864,7 @@ config CPU_LOONGSON2
 config CPU_LOONGSON1
 	bool
 	select CPU_MIPS32
-	select CPU_MIPSR1
+	select CPU_MIPSR2
 	select CPU_HAS_PREFETCH
 	select CPU_HAS_LOAD_STORE_LR
 	select CPU_SUPPORTS_32BIT_KERNEL

arch/mips/loongson32/Platform

-cflags-$(CONFIG_CPU_LOONGSON1)		+= -march=mips32 -Wa,--trap
+cflags-$(CONFIG_CPU_LOONGSON1)		+= -march=mips32r2 -Wa,--trap
 platform-$(CONFIG_MACH_LOONGSON32)	+= loongson32/
 cflags-$(CONFIG_MACH_LOONGSON32)	+= -I$(srctree)/arch/mips/include/asm/mach-loongson32
 load-$(CONFIG_CPU_LOONGSON1)		+= 0xffffffff80200000