msm: kgsl: Enable special case performance counters

Special case performance counters do not have select registers.
Enabling performance counters first checks that the counters we want
are valid and have select registers, then it would enable the counters.
The special case performance registers were not being enabled in this
case since they fail the initial test.  Move these special cases to
before the select register error checking and perform their own sanity
checks before enabling the performance counters

Change-Id: I716103fb6bfb97ba3e198503531af139fb1725f8
Signed-off-by: Carter Cooper <ccooper@codeaurora.org>