ARM: dts: dra7: add crossbar device binding

There is a IRQ crossbar device in the soc, which
maps the irq requests from the peripherals to the
mpu interrupt controller's inputs. The Peripheral irq
requests are connected to only one crossbar
input and the output of the crossbar is connected to only one
controller's input line. The crossbar device is used to map
a peripheral input to a free mpu's interrupt controller line.

Here, adding a new crossbar device node and replacing all the peripheral
interrupt numbers with its fixed crossbar input lines.
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>