ARM: 6252/1: Use SIGBUS for unaligned access instead of SIGILL

POSIX specify to use signal SIGBUS with code BUS_ADRALN for invalid
address alignment.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>