clocksource/drivers/sh_cmt: r8a7740 and sh73a0 SoC-specific match

Add SoC-specific matching for CMT1 on r8a7740 and sh73a0.

This allows us to move away from the old DT bindings such as
 - "renesas,cmt-48-sh73a0"
 - "renesas,cmt-48-r8a7740"
 - "renesas,cmt-48"
in favour for the now commonly used format "renesas,<soc>-<device>"

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>