lib: introduce HASH_CALCULATE option

Build error occurs when CONFIG_EFI_SECURE_BOOT or
CONFIG_EFI_CAPSULE_AUTHENTICATE is enabled,
because hash-checksum.c is not compiled.

Since hash_calculate() implemented in hash-checksum.c can be
commonly used aside from FIT image signature verification,
this commit itroduces HASH_CALCULATE option to decide
if hash-checksum.c shall be compiled.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>