ARM: orion5x: cleanup unneeded code on RD-88F5182-NAS DT

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
ARM: orion5x: use DT to describe NOR on edmini_v2

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
ARM: orion5x: keep TODO list in edmini_v2 DT

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
ARM: orion5x: remove unneeded code for edmini_v2

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
ARM: orion: remove no longer needed DT IRQ code

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>