tty: serial: msm_geni_serial: Add get_mctrl console operation

Add get_mctrl operation for console port so that reading the input control
signals does not cause any error.

When the system OOPS is in progress, try locking the console port
lock. If the locking fails, return immediately to avoid any recursive
locking.

Also when the UART port is shutdown stop the console followed by stopping
the TX/RX while holding the port lock. This will ensure that the port
shutdown operation does not prematurely stop the concerned serial engine
while another thread is waiting for the TX/RX lock.

CRs-Fixed: 2052028
Change-Id: Iaac8045dbad100e3754b88480869202ddce84b99
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>