[RFC PATCH] ARM64: dts: Add support for Meson GXM

Neil Armstrong [off-list ref] writes:

Following the Amlogic Linux kernel, it seem the only differences
between the GXL and GXM SoCs are the CPU Clusters.

Simply add a meson-gxm dtsi and reproduce the P23x to Q20x boards
dts files since the S905D and S912 SoCs shares the same pinout
and the P23x and Q20x boards are identical.

Since the P23x and Q20x boards are identical, should we just come up
with a singel dtsi for them all? e.g  move the -p23x.dtsi to -pq2xx.dtsi
or something?

I don't think it's a big deal, but it does seem like we should avoid the
copy/paste wherever possible.

Kevin