msm: clock-8974: Fix GPLL0 configuration issue for acpuclock

GPLL0 is always expected to be on when Linux is running. It is required
for all active BMIC/EBI and NoC clock rates. acpuclock also makes the
assumption that GPLL0_AUX is an always-on source that can be safely
switched to at any time. For current builds used in pre-silicon
simulation environments, however, this is not true because:

 1) The bootchain and RPM, which would normally vote for GPLL0 to remain
    enabled are not presently in use, leaving clock-8974 as the only
    voter for the PLL.

 2) The clock driver de-asserts its vote for GPLL0 when there are no clock
    driver clients requiring it, resulting in it turning off.

 3) The AUX output of GPLL0 is never enabled due a typo in reg_init()

The first point was already addressed in clock-8974.c be enabling GPLL0 as
part of reg_init().

The second point is addressed now, by removing the enable mask for GPLL0.
This is simpler and more efficient than requiring acpuclock to vote for
the PLL. It also avoid the side-effect of blocking XO-shutdown that such
a vote would have if power-collapse were to occur while the CPU is running
from the PLL0 source (which should be allowed).

The third point is also addressed now by correcting the "PLL_AUX_OUTPUT"
macro.

Change-Id: I5abeb6497261119fd1ae674f8b901d360261932f
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>