This consolidates the various board heartbeat LED implementations,
used for strobing the load average across a LED bank. Those boards
not implementing a full bank can hook in via the LED class.

We leave the compat hook in the machvec for now until those non-banked
boards are able to migrate to the drivers/leds.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds simple push-switch support for the RDBRP-1/RDBREVRP-1 debug
boards found on the R7780RP-1.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds support for the Renesas SH7780 development boards,
R7780RP and R7780MP.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>