ARM: 6342/1: fix ASLR of PIE executables

Since commits 990cb8ac and cc92c28b

, it is possible to have full
address space layout randomization (ASLR) on ARM.  Except that one small
change was missing for ASLR of PIE executables.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>