crypto: sha1-mb - rename sha-mb to sha1-mb

Until now, there was only support for the SHA1 multibuffer algorithm.
Hence, there was just one sha-mb folder. Now, with the introduction of
the SHA256 multi-buffer algorithm , it is logical to name the existing
folder as sha1-mb.

Signed-off-by: Megha Dey <megha.dey@linux.intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>