crypto: x86/sha - Restructure x86 sha1 glue code to expose all the available sha1 transforms

Restructure the x86 sha1 glue code so we will expose sha1 transforms based
on SSSE3, AVX, AVX2 or SHA-NI extension as separate individual drivers
when cpu provides such support. This will make it easy for alternative
algorithms to be used if desired and makes the code cleaner and easier
to maintain.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>