mips: add HWCAP_ flags from linux v4.17

new in linux commit 256211f2b0b251e532d1899b115e374feb16fa7a

arch/mips/bits/hwcap.h

@@ -1,2 +1,3 @@
 #define HWCAP_MIPS_R6		(1 << 0)
 #define HWCAP_MIPS_MSA		(1 << 1)
+#define HWCAP_MIPS_CRC32	(1 << 2)

arch/mips64/bits/hwcap.h

@@ -1,2 +1,3 @@
 #define HWCAP_MIPS_R6		(1 << 0)
 #define HWCAP_MIPS_MSA		(1 << 1)
+#define HWCAP_MIPS_CRC32	(1 << 2)

arch/mipsn32/bits/hwcap.h

@@ -1,2 +1,3 @@
 #define HWCAP_MIPS_R6		(1 << 0)
 #define HWCAP_MIPS_MSA		(1 << 1)
+#define HWCAP_MIPS_CRC32	(1 << 2)