Add quirk for ignoring SPCR AccessWidth values on the PL011 UART

The SPCR table on the Lenovo HR330A Ampere eMAG server indicates 8-bit
access, but 32-bit access is required for the PL011 to work.

PL011 on SBSA platforms always supports 32-bit access (and that was
hardcoded here before my EC2 fix), let's use 32-bit access for PL011
and 32BIT interface types.

Tested by emaste on Ampere eMAG and Cavium/Marvell ThunderX2.

Submitted by: Greg V <greg@unrelenting.technology>
Reviewed by: andrew, imp (earlier)
Differential Revision: https://reviews.freebsd.org/D19507