common/spl: Drop [ST]PL_HASH_SUPPORT in favor of [ST]PL_HASH

All of these configs exist. Stick to using CONFIG_[ST]PL_HASH, and drop all
references to CONFIG_[ST]PL_HASH_SUPPORT.  This means we need for
CHAIN_OF_TRUST to select SPL_HASH now.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
[trini: Add TPL case, fix CHAIN_OF_TRUST, other tweaks]
Signed-off-by: Tom Rini <trini@konsulko.com>