i2c: imx-lpi2c: add VLLS mode support

When system enters VLLS mode, module power is turned off. As a result,
all registers are reset to HW default value. After exiting VLLS mode,
registers are still in default mode. As a result, the pinctrl settings
are incorrect, which will affect the module function.

The patch recovers the pinctrl setting when exit VLLS mode.

Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
[wsa: added missing include]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>