The patch aligns to the IntelFrameworkModulePkg/Bus/Isa/IsaSerialDxe
driver not flush the UART in Reset() and SetAttributes() function.
It was found the flush causes hang on certain PCI serial devices.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Eric Jin <eric.jin@intel.com>