`checkpatch.pl` requires that dts sources are indented with tabs,
fix all the spaces that slipped in while checkpatch wasn't watching.
Signed-off-by: Jordan Yates <jordan@embeint.com>
As the cadence uart, has no off-the-shelve microprocessor out there.
Add a build only test case for the cadence uart using the qemu cortex
m3 as the board.
Signed-off-by: Ryan McClelland <ryanmcclelland@meta.com>
