mips: add hwcap bits from linux v5.4

mips application specific isa extensions were previously not exported
in hwcaps so userspace could not apply optimized code at runtime.

  linux commit 38dffe1e4dde1d3174fdce09d67370412843ebb5
  MIPS: elf_hwcap: Export userspace ASEs

arch/mips/bits/hwcap.h

@@ -1,3 +1,14 @@
 #define HWCAP_MIPS_R6		(1 << 0)
 #define HWCAP_MIPS_MSA		(1 << 1)
 #define HWCAP_MIPS_CRC32	(1 << 2)
+#define HWCAP_MIPS_MIPS16	(1 << 3)
+#define HWCAP_MIPS_MDMX		(1 << 4)
+#define HWCAP_MIPS_MIPS3D	(1 << 5)
+#define HWCAP_MIPS_SMARTMIPS	(1 << 6)
+#define HWCAP_MIPS_DSP		(1 << 7)
+#define HWCAP_MIPS_DSP2		(1 << 8)
+#define HWCAP_MIPS_DSP3		(1 << 9)
+#define HWCAP_MIPS_MIPS16E2	(1 << 10)
+#define HWCAP_LOONGSON_MMI	(1 << 11)
+#define HWCAP_LOONGSON_EXT	(1 << 12)
+#define HWCAP_LOONGSON_EXT2	(1 << 13)