MdeModulePkg/NonDiscoverablePciDev: Fix type mismatch in switch/case

MdeModulePkg/NonDiscoverablePciDev: Fix type mismatch in switch/case

Fix switch/case statement type mismatch in functions PciIoMemRead &
PciIoMemWrite.

Parameter 'Width' is of enum type EFI_PCI_IO_PROTOCOL_WIDTH, but the enum
type provided in 'switch (Width)' block is of type
EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>