Avoid unconditional context restore every time we gate uart
clocks. Check whether context loss happened based on which
we can context restore uart regs from uart_port structure.
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> (for drivers/tty changes)
Signed-off-by: Kevin Hilman <khilman@ti.com>