staging: most: dim2: force fcnt=3 on Renesas GEN3

Per Renesas datasheet, MLBC0 register's fcnt field in the embedded
dim2 module must be never set to value different from 3.

Enforce that, via an optional field in struct dim2_platform_data.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Link: https://lore.kernel.org/r/20210927155804.27877-1-nikita.yoush@cogentembedded.com


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