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 87316da05f ("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>

lib/Makefile

@@ -61,7 +61,7 @@ endif
 obj-$(CONFIG_$(SPL_)ACPIGEN) += acpi/
 obj-$(CONFIG_$(SPL_)MD5) += md5.o
 obj-$(CONFIG_$(SPL_)RSA) += rsa/
-obj-$(CONFIG_FIT_SIGNATURE) += hash-checksum.o
+obj-$(CONFIG_HASH) += hash-checksum.o
 obj-$(CONFIG_SHA1) += sha1.o
 obj-$(CONFIG_SHA256) += sha256.o
 obj-$(CONFIG_SHA512_ALGO) += sha512.o

lib/efi_loader/Kconfig

@@ -166,6 +166,7 @@ config EFI_CAPSULE_AUTHENTICATE
 	depends on EFI_CAPSULE_FIRMWARE
 	depends on EFI_CAPSULE_ON_DISK
 	depends on EFI_CAPSULE_FIRMWARE_MANAGEMENT
+	select HASH
 	select SHA256
 	select RSA
 	select RSA_VERIFY
@@ -334,6 +335,7 @@ config EFI_LOAD_FILE2_INITRD
 config EFI_SECURE_BOOT
 	bool "Enable EFI secure boot support"
 	depends on EFI_LOADER
+	select HASH
 	select SHA256
 	select RSA
 	select RSA_VERIFY_WITH_PKEY