msm: ipa: remove ipa clock proxy vote after uC loading is complete

This change resolves a case where the IPA clock proxy vote is
removed too early (when QMI handshake is complete) while uC loading
indication hasn't been received yet. In this case, it is possible
that IPA will go to clock gating / power collapse, and upon receiving
a "uC loaded" event, the shared memory contents will be empty (all zeroes)
and the driver will miss the indication.

CRs-Fixed: 863218
Change-Id: I82071a9f9f2d5e876cd5227215491519ea906f24
Signed-off-by: Sivan Reinstein <sivanr@codeaurora.org>
Acked-by: David Arinzon <darinzon@qti.qualcomm.com>