tty: serial: qcom-geni-serial: Add support for Hibernation feature

Added changes to support the hibernation feature for serial UART.
Added support for freeze, restore and thaw callbacks to put the
device into hibernation.

Signed-off-by: Aniket Randive <quic_arandive@quicinc.com>
Link: https://lore.kernel.org/r/1665123780-20557-1-git-send-email-quic_arandive@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>