powerpc: Enable GCOV

Make it possible to enable GCOV code coverage measurement on powerpc.

Lightly tested on 64-bit, seems to work as expected.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/vdso64/Makefile b/arch/powerpc/kernel/vdso64/Makefile
index fa7f1b8..dd0c8e9 100644
--- a/arch/powerpc/kernel/vdso64/Makefile
+++ b/arch/powerpc/kernel/vdso64/Makefile
@@ -7,6 +7,8 @@
 targets := $(obj-vdso64) vdso64.so vdso64.so.dbg
 obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
 
+GCOV_PROFILE := n
+
 EXTRA_CFLAGS := -shared -fno-common -fno-builtin
 EXTRA_CFLAGS += -nostdlib -Wl,-soname=linux-vdso64.so.1 \
 		$(call ld-option, -Wl$(comma)--hash-style=sysv)