serial: qcom: add support for GENI serial driver

Generic Interface (GENI) Serial Engine (SE) based uart
can be found on newer qualcomm SOCs, starting from SDM845.
Tested on Samsung SM-G9600(starqltechn)
by chain-loading u-boot with stock bootloader.

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Tom Rini <trini@konsulko.com>