staging: most: dim2: use consistent routine naming

Rename init routines and enum values to reflect that those are for
Renesas R-Car Gen2 and R-Car Gen3 SoCs.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Link: https://lore.kernel.org/r/20211226082530.2245198-3-nikita.yoush@cogentembedded.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>