sh: Add sh to the CC_OPTIMIZE_FOR_SIZE dependencies.

Presently we only use this with CONFIG_EXPERIMENTAL, but it is
something that can be supported commonly.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

init/Kconfig

@@ -340,7 +340,7 @@ endif
 config CC_OPTIMIZE_FOR_SIZE
 	bool "Optimize for size (Look out for broken compilers!)"
 	default y
-	depends on ARM || H8300 || EXPERIMENTAL
+	depends on ARM || H8300 || SUPERH || EXPERIMENTAL
 	help
 	  Enabling this option will pass "-Os" instead of "-O2" to gcc
 	  resulting in a smaller kernel.