arm: kirkwood: iconnect: give meaningful names to pinmux configs
The Kirkwood iConnect Device Tree is currently using totally
meaningless names for the pinmux configuration: pmx_gpio_XY.
This patch fixes that by using some more meaningful names such as
pmx_button_power.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Acked-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Jason Cooper <jason@lakedaemon.net>