powerpc/vmlinux.lds: Add .text.asan/tsan sections

When KASAN/KCSAN are enabled clang generates .text.asan/tsan sections.
Because they are not mentioned in the linker script warnings are
generated, and when orphan handling is set to error that becomes a build
error, eg:

  ld.lld: error: vmlinux.a(init/main.o):(.text.tsan.module_ctor) is
  being placed in '.text.tsan.module_ctor' ld.lld: error:
  vmlinux.a(init/version.o):(.text.tsan.module_ctor) is being placed in
  '.text.tsan.module_ctor'

Fix it by adding the sections to our linker script, similar to the
generic change made in 84837881 ("vmlinux.lds.h: Handle clang's
module.{c,d}tor sections").
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230222060037.2897169-1-mpe@ellerman.id.au

arch/powerpc/kernel/vmlinux.lds.S

@@ -124,6 +124,7 @@ SECTIONS
 		 * included with the main text sections, so put it by itself.
 		 */
 		*(.sfpr);
+		*(.text.asan.* .text.tsan.*)
 		MEM_KEEP(init.text)
 		MEM_KEEP(exit.text)
 	} :text