regmap: mmio: replace return 0 with break in switch statement

Variable min_stride is assigned a value that is never read, fix this by
replacing the return 0 with a break statement. This also makes the case
statement consistent with the other cases in the switch statement.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220922080445.818020-1-colin.i.king@gmail.com


Signed-off-by: Mark Brown <broonie@kernel.org>