ARM: imx: mx5: Convert MX53 Menlo board to DM I2C and DM RTC

Convert the board to DM I2C and DM RTC. This leads to removal of board
side iomuxc configuration, which is now done using pin control driver,
and conversion of board side legacy I2C accessors to DM ones.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>