tty: pl011: Add suspend resume support

Add the suspend and resume handlers for the versal uart platform driver.
Adds the suspend for sbsa driver.
Sbsa is a subset of the pl011 driver.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1575873048-14313-1-git-send-email-shubhrajyoti.datta@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>