ARM64: reloc_test: add missing MODULE_DESCRIPTION() macro

With ARCH=arm64, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/arm64/kernel/arm64-reloc-test.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240612-md-arch-arm64-kernel-v1-1-1fafe8d11df3@quicinc.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>