MIPS: Replace CONFIG_MIPS64 and CONFIG_MIPS32_R2

Commit 597ce1723e0f ("MIPS: Support for 64-bit FP with O32 binaries")
introduced references to two undefined Kconfig macros. CONFIG_MIPS32_R2
should clearly be replaced with CONFIG_CPU_MIPS32_R2. And CONFIG_MIPS64
should be replaced with CONFIG_64BIT.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/6522/
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h
index 6b97495..58e50cb 100644
--- a/arch/mips/include/asm/fpu.h
+++ b/arch/mips/include/asm/fpu.h
@@ -57,7 +57,7 @@
 		return 0;
 
 	case FPU_64BIT:
-#if !(defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_MIPS64))
+#if !(defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_64BIT))
 		/* we only have a 32-bit FPU */
 		return SIGFPE;
 #endif