arm64: dts: ti: k3-am65/j721e-main: rename gic-its node to msi-controller

arm64: dts: ti: k3-am65/j721e-main: rename gic-its node to msi-controller

The preferable name for gic-its is msi-controller, so rename it to fix
dtbs_check warning:

k3-j721e-common-proc-board.dt.yaml: interrupt-controller@1800000:
gic-its@1820000: False schema does not allow {'compatible':
['arm,gic-v3-its'], 'reg': [[0, 25296896, 0, 65536]],
'socionext,synquacer-pre-its': [[16777216, 4194304]], 'msi-controller':
True, '#msi-cells': [[1]]}

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>