serial: msm_geni_serial: Call console_stop during shutdown

In some scenarios if there is a call to close the console device then
it is possble there could be attempts to use console framework to print
messages as it is possible an explicit stop hasn't been made to printk.
In these cases if printk does try to send messages to the console driver
a bus error could result as the resources for the port are already
removed.

Change-Id: Ib241361f878b8c1cd1448b13123c35fc6162a234
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>