tools build: Fix objtool build with clang

Clang doesn't support multiple arguments being passed to -Wp, so split
them.

  Fixes this error:
  HOSTCC   tools/objtool/fixdep.o
  cat: tools/objtool/.fixdep.o.d: No such file or directory

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20161128024346.17371-1-pefoley2@pefoley.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/build/Build.include

@@ -89,12 +89,12 @@ if_changed = $(if $(strip $(any-prereq) $(arg-check)),             \
 # - per target C flags
 # - per object C flags
 # - BUILD_STR macro to allow '-D"$(variable)"' constructs
-c_flags_1 = -Wp,-MD,$(depfile),-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj))
+c_flags_1 = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CFLAGS) -D"BUILD_STR(s)=\#s" $(CFLAGS_$(basetarget).o) $(CFLAGS_$(obj))
 c_flags_2 = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(c_flags_1))
 c_flags   = $(filter-out $(CFLAGS_REMOVE_$(obj)), $(c_flags_2))
-cxx_flags = -Wp,-MD,$(depfile),-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj))
+cxx_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CXXFLAGS) -D"BUILD_STR(s)=\#s" $(CXXFLAGS_$(basetarget).o) $(CXXFLAGS_$(obj))
 
 ###
 ## HOSTCC C flags
 
-host_c_flags = -Wp,-MD,$(depfile),-MT,$@ $(CHOSTFLAGS) -D"BUILD_STR(s)=\#s" $(CHOSTFLAGS_$(basetarget).o) $(CHOSTFLAGS_$(obj))
+host_c_flags = -Wp,-MD,$(depfile) -Wp,-MT,$@ $(CHOSTFLAGS) -D"BUILD_STR(s)=\#s" $(CHOSTFLAGS_$(basetarget).o) $(CHOSTFLAGS_$(obj))