The driver queries the CCI IP revision to distinguish between r0 and r1
scheme for event numbers and currently supports upto version r1p2. To
minimise code churn every time there's a new version of the IP, assume
that event numbering doesn't change for revisions > r1p0 (which is
the case).

The driver will still need an update for future revisions that change
the event numbers.
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>