efi_loader: Work-around build issue due to missing hash_calculate()

efi_loader: Work-around build issue due to missing hash_calculate()

The hash_calculate() symbol is provided by hash-checksum.c. It depends
on hash_progressive_lookup_algo(), provided when CONFIG_HASH=y.

The issue is that hash_calculate() is used by the efi_loader,
irregardless of CONFIG_FIT_SIGNATURE. As pointed out in
commit 87316da05f2f ("lib: introduce HASH_CALCULATE option"),
enabling hash_calculate() based on CONFIG_FIT_SIGNATURE is incorrect.

To resolve this, use CONFIG_HASH as the compile switch for
hash-checksum.c. This ensures that all dependencies are compiled, and
is the most natural Kconfig to use.

There is the issue of having to 'select HASH' in a couple of places
that already 'select SHA256'. This is a deeper problem with how hashes
are organized, and fixing it is beyonf the scope of this change.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Acked-by: Masahisa Kojima <masahisa.kojima@linaro.org>