tests: Add lib/memcpy-test test case

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: I00464ec2db23867712cd2efd7f6cad92e3ee361a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50799
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>

tests/lib/Makefile.inc

@@ -17,6 +17,7 @@ tests-y += stack-test
 tests-y += memset-test
 tests-y += memcmp-test
 tests-y += memchr-test
+tests-y += memcpy-test
 
 string-test-srcs += tests/lib/string-test.c
 string-test-srcs += src/lib/string.c
@@ -88,3 +89,5 @@ memcmp-test-srcs += tests/lib/memcmp-test.c
 memchr-test-srcs += tests/lib/memchr-test.c
 memchr-test-srcs += src/lib/memchr.c
 
+memcpy-test-srcs += tests/lib/memcpy-test.c
+