arm: apple: Disable debug UART

The address of the debug UART varies differs between the M1 and
the M1 Pro/Max SoCs.  So we have to disable it to make a single
U-Boot binary that works on all SoC generations.  Leave the
settings for the base address and clock rate of the M1 in place
to make it easier to re-enable the debug UART when needed.

Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
1 file changed