New board, EHL CRB, does not have legacy port IO UART. Even the PCI UART
are not work due to BIOS's bug workaround(the BARs on LPSS PCI are reset
after BIOS hand over control to OS). For ACRN console usage, expose the
debug UART via ACPI PnP device (access by MMIO) and add support in
hypervisor debug code.
Another special thing is that register width of UART of EHL CRB is
1byte. Introduce reg_width for each struct console_uart.
Tracked-On: #4937
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>