mailbox: remove unneeded 'fast_io' parameter in regmap_config

When using MMIO with regmap, fast_io is implied. No need to set it
again.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
1 file changed