arm/mach-meson: move smc commands in cmd/meson

It is incorrect to keep commands in the arch/ folder.

Signed-off-by: Alexey Romanov <avromanov@sberdevices.ru>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20230110105650.54580-3-avromanov@sberdevices.ru
[narmstrong: moved after cmd/sound in index.rst]
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 237f394..dda5067 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -149,6 +149,7 @@
 T:	git https://source.denx.de/u-boot/custodians/u-boot-amlogic.git
 F:	arch/arm/mach-meson/
 F:	arch/arm/include/asm/arch-meson/
+F:	cmd/meson/
 F:	drivers/clk/meson/
 F:	drivers/serial/serial_meson.c
 F:	drivers/reset/reset-meson.c