ARM: dts: r8a73a4: Update CMT compat string

Use the recently updated r8a73a4 CMT1 compat string.

With this change in place we can keep device-specific configuration in
the driver and the driver can be able to support CMT1 specific features.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>