x86/cpufeatures: Enable cpuid for Intel SHA extensions

x86/cpufeatures: Enable cpuid for Intel SHA extensions

Add Intel CPUID for Intel Secure Hash Algorithm Extensions. This feature
provides new instructions for accelerated computation of SHA-1 and SHA-256.
This allows the feature to be shown in the /proc/cpuinfo for cpus that
support it.

Refer to SHA extension programming guide in chapter 8.2 of the Intel
Architecture Instruction Set Extensions Programming reference
for definition of this feature's cpuid: CPUID.(EAX=07H, ECX=0):EBX.SHA [bit 29] = 1
https://software.intel.com/sites/default/files/managed/07/b7/319433-023.pdf

Originally-by: Chandramouli Narayanan <mouli_7982@yahoo.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Link: http://lkml.kernel.org/r/1440194206.3940.6.camel@schen9-mobl2
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>