ARM: at91: dts: sama5d3: change name of pinctrl_isi_{power,reset}
For sama5d3xmb board, the pins: pinctrl_isi_{power,reset} is used to
power-down or reset camera sensor.
So we should let camera sensor instead of ISI to configure the pins.
This patch will change pinctrl name from pinctrl_isi_{power,reset} to
pinctrl_sensor_{power,reset}. And remove these two pinctrl from ISI's
DT node. We will add these two pinctrl to sensor's DT node.