cbfs/vboot: Adapt to new vb2_digest API

CL:3825558 changes all vb2_digest and vb2_hash functions to take a new
hwcrypto_allowed argument, to potentially let them try to call the
vb2ex_hwcrypto API for hash calculation. This change will open hardware
crypto acceleration up to all hash calculations in coreboot (most
notably CBFS verification). As part of this change, the
vb2_digest_buffer() function has been removed, so replace existing
instances in coreboot with the newer vb2_hash_calculate() API.

Due to the circular dependency of these changes with vboot, this patch
also needs to update the vboot submodule:

Updating from commit id 18cb85b5:
    2load_kernel.c: Expose load kernel as vb2_api

to commit id b827ddb9:
    tests: Ensure auxfw sync runs after EC sync

This brings in 15 new commits.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I287d8dac3c49ad7ea3e18a015874ce8d610ec67e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66561
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jakub Czapiga <jacz@semihalf.com>

payloads/libpayload/tests/libcbfs/cbfs-verification-test.c

@@ -23,8 +23,10 @@ size_t vb2_digest_size(enum vb2_hash_algorithm hash_alg)
 	return VB2_SHA256_DIGEST_SIZE;
 }
 
-vb2_error_t vb2_hash_verify(const void *buf, uint32_t size, const struct vb2_hash *hash)
+vb2_error_t vb2_hash_verify(bool allow_hwcrypto, const void *buf, uint32_t size,
+			    const struct vb2_hash *hash)
 {
+	assert_true(allow_hwcrypto);
 	check_expected_ptr(buf);
 	check_expected(size);