x86, cpufeature: Add the RDSEED and ADX features

Add the RDSEED and ADX features documented in section 9.1 of the Intel
Architecture Instruction Set Extensions Programming Reference,
document 319433, version 013b, available from
http://software.intel.com/en-us/avx/

The PREFETCHW bit is already supported in Linux under the name
3DNOWPREFETCH.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-lgr6482ufk1bvxzvc2hr8qbp@git.kernel.org

arch/x86/include/asm/cpufeature.h

@@ -207,6 +207,8 @@
 #define X86_FEATURE_ERMS	(9*32+ 9) /* Enhanced REP MOVSB/STOSB */
 #define X86_FEATURE_INVPCID	(9*32+10) /* Invalidate Processor Context ID */
 #define X86_FEATURE_RTM		(9*32+11) /* Restricted Transactional Memory */
+#define X86_FEATURE_RDSEED	(9*32+18) /* The RDSEED instruction */
+#define X86_FEATURE_ADX		(9*32+19) /* The ADCX and ADOX instructions */
 
 #if defined(__KERNEL__) && !defined(__ASSEMBLY__)