pinctrl: mvebu: remove passing mvebu_mpp_ctrl to callbacks

The only valuable information a special callback can derive from
mvebu_mpp_ctrl passed to it, is the pin id. Instead of passing
the struct, pass the pid directly.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>