arm: oprofile: Add OProfile support for 7x27a or Cortex A5 cpu type

This patch adds support to recognise cortex A5 cputype for oprofile,
which in turn enables the armv7 generic events to be picked.

Change-Id: I025f4b361b4e85bbeea4eefc71572f4ae5b602e4
Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
(cherry picked from commit 1540f31eb76f2e775d1a04edb6d9f8397d4f6637)