spl: cypto: Bring back SPL_ versions of SHA

Unfortunately these were removed by mistake. This means that adding hash
support to SPL brings in all software algorithms, with a substantial
increase in code size.

The origin of the problem was renaming them to SPL_FIT_xxx and then these
were removed altogether in a later commit.

Add them back. This aligns with CONFIG_MD5, for example, which has an SPL
variant.

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: f5bc9c25 ("image: Rename SPL_SHAxxx_SUPPORT to SPL_FIT_SHAxxx")
Fixes: eb5171dd ("common: Remove unused CONFIG_FIT_SHAxxx selectors")
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>