MLK-20773 i2c-imx: add a limit of maximum transfer speed for imx7d

MLK-20773 i2c-imx: add a limit of maximum transfer speed for imx7d

According the e7805 in Errata, the SCK low level period should be less
than 1.3us.

The other series platform use this same IP can match the errata, and
ensure the low level period longer than 1.3us when the speed set to
400KHz. However, only at imx7d platform, the low level period is less
than 1.3us in the same situation.

Therefore, limit the maximum transfer speed to 384KHz when probe at
imx7d platform.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
(cherry picked from commit 19f553846e872b5c379b37ed029132b79566cab0)