ARM: 7591/1: nommu: Enable the strict alignment (CR_A) bit only if ARCH < v6

This patch keeps disabled the strict alignment CP15 bit for
all armv6 and armv7 processor without the mmu. This behaviour
is now same as in the mmu case.

Signed-off-by: Armando Visconti <armando.visconti@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>