Adding comment describing the r8a7779 clock frequencies depending on
MD pin settings.
Acked-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>