drivers: cci: Export CCI PMU revision

The event numbering changed between revision r0 and r1 of the CCI
PMU. Expose this to userspace to allow tooling to handle the
differences in event numbers.

Change-Id: I89129ee934b7e86609f0c8dc62484df66c9aea54
Suggested-by: Drew Richardson <Drew.Richardson@arm.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Git-commit: dc4409c0062d7e40fe523abc06310281ba666369
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Neil Leeder <nleeder@codeaurora.org>