sparc: vdso: fix build error of vdso32

Since commit 54b8ae66 ("kbuild: change *FLAGS_<basetarget>.o to
take the path relative to $(obj)"), sparc allmodconfig fails to build
as follows:

  CC      arch/sparc/vdso/vdso32/vclock_gettime.o
unrecognized e_machine 18 arch/sparc/vdso/vdso32/vclock_gettime.o
arch/sparc/vdso/vdso32/vclock_gettime.o: failed

The cause of the breakage is that -pg flag not being dropped.

The vdso32 files are located in the vdso32/ subdirectory, but I missed
to update the Makefile.

I removed the meaningless CFLAGS_REMOVE_vdso-note.o since it is only
effective for C file.

vdso-note.o is compiled from assembly file:

  arch/sparc/vdso/vdso-note.S
  arch/sparc/vdso/vdso32/vdso-note.S

Fixes: 54b8ae66 ("kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)")
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>