selftests/powerpc/ptrace: Set LOCAL_HDRS

Set LOCAL_HDRS so header changes cause rebuilds. The lib.mk logic adds
all the headers in LOCAL_HDRS as dependencies, so there's no need to
also list them explicitly.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220627140239.2464900-2-mpe@ellerman.id.au

tools/testing/selftests/powerpc/ptrace/Makefile

@@ -4,12 +4,13 @@ TEST_GEN_PROGS := ptrace-gpr ptrace-tm-gpr ptrace-tm-spd-gpr \
               ptrace-tm-spd-vsx ptrace-tm-spr ptrace-hwbreak ptrace-pkey core-pkey \
               perf-hwbreak ptrace-syscall ptrace-perf-hwbreak
 
+LOCAL_HDRS += $(patsubst %,$(selfdir)/powerpc/ptrace/%,$(wildcard *.h))
+
 top_srcdir = ../../../../..
 include ../../lib.mk
 
 CFLAGS += -m64 -I../../../../../usr/include -I../tm -mhtm -fno-pie
 
-$(OUTPUT)/ptrace-pkey $(OUTPUT)/core-pkey: child.h
 $(OUTPUT)/ptrace-pkey $(OUTPUT)/core-pkey: LDLIBS += -pthread
 
-$(TEST_GEN_PROGS): ../harness.c ../utils.c ../lib/reg.S ptrace.h
+$(TEST_GEN_PROGS): ../harness.c ../utils.c ../lib/reg.S