sh: Clean up linker script using new linker script macros.

This patch converts the sh architecture to use the new linker script
macros in include/asm-generic/vmlinux.lds.h.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: linux-sh@vger.kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>