serial: msm_geni_serial: Remove proxy driver resource vote for HS UART

The driver currently puts in a runtime vote to keep the required resources
on at the time the UART port is opened and removes it when the port is
closed.
Instead, remove the vote as soon as the port open function completes for
HS UART. For HS UART the client drivers put in a request for the resources
to be voted on before any data path or control path operations.

Change-Id: Ide5e8cf43cafeae1baccde9ee45e81ddd1a203b7
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>