sparc32: fix sparse warnings in unaligned_32.c

Fix following warnings:
unaligned_32.c:146:15: warning: symbol 'safe_compute_effective_address' was not declared. Should it be static?
unaligned_32.c:235:17: warning: symbol 'kernel_unaligned_trap' was not declared. Should it be static?
unaligned_32.c:319:17: warning: symbol 'user_unaligned_trap' was not declared. Should it be static?

Add proper declarations in kernel.h + setup.h

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>