sh: Clean up linker script using new BSS_SECTION macro.

Updated to use the fixed BSS linker script macros from this
thread:

	http://www.spinics.net/lists/kernel/msg913238.html



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