serial: 8250_fsl: Add ACPI support

This adds support for ACPI enumerated FSL 16550 UARTs.
For supporting ACPI, I added a wrapper so that this driver
can be used if firmware has exposed the HID "NXP0018" in
DSDT table.

This will be built as object file if config "SERIAL_8250_FSL"
is enabled which depends on config "SERIAL_8250_CONSOLE".

Signed-off-by: kuldip dwivedi <kuldip.dwivedi@puresoftware.com>
Link: https://lore.kernel.org/r/20200903113402.12371-1-kuldip.dwivedi@puresoftware.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>