tty: serial: msm_serial: Remove console unregistration from driver exit.

unregister_console() will be called from uart_remove_one_port() while
removing the platform driver. So not necessary to call it in driver
exit path.

Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>