selftests: sparc64: Add missing SPDX License Identifiers

Add missing SPDX License Identifiers to Makefile(s).
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Reviewed-by: Tom Hromatka <tom.hromatka@oracle.com>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

tools/testing/selftests/sparc64/Makefile

+# SPDX-License-Identifier: GPL-2.0
 uname_M := $(shell uname -m 2>/dev/null || echo not)
 ARCH ?= $(shell echo $(uname_M) | sed -e s/x86_64/x86/)
 

tools/testing/selftests/sparc64/drivers/Makefile

-
+# SPDX-License-Identifier: GPL-2.0
 INCLUDEDIR := -I.
 CFLAGS := $(CFLAGS) $(INCLUDEDIR) -Wall -O2 -g