sh: Fix build with CONFIG_UBSAN=y

The early boot stub for sh had UBSan instrumentation present where it is
not supported. Disable it for this part of the build.

  sh4-linux-ld: arch/sh/boot/compressed/misc.o: in function `zlib_inflate_table':
  misc.c:(.text+0x670): undefined reference to `__ubsan_handle_shift_out_of_bounds'

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401310416.s8HLiLnC-lkp@intel.com/
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nicolas Schier <n.schier@avm.de>
Cc:  <linux-sh@vger.kernel.org>
Link: https://lore.kernel.org/r/20240130232717.work.088-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

arch/sh/boot/compressed/Makefile

@@ -12,6 +12,7 @@ targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 \
            vmlinux.bin.lzma vmlinux.bin.xz vmlinux.bin.lzo $(OBJECTS)
 
 GCOV_PROFILE := n
+UBSAN_SANITIZE := n
 
 #
 # IMAGE_OFFSET is the load offset of the compression loader