arm64: dts: ti: k3-j721e: Add gpio nodes in main domain

There are 8 instances of gpio modules in main domain divided into 2 groups:
- Group1: gpio0, gpio2, gpio4, gpio6
- Group2: gpio1, gpio3, gpio5, gpio7

Groups are created to provide protection between two different processor
virtual worlds. There are x gpio lines coming out of each group. Each module
in a group has equal x gpio lines pinned out. There is a top level mux for
selecting the module instance for each pin coming out of group. Exactly
one module can be selected to control the corresponding pin. This muxing
can be controlled along the pad mux configuration registers.

Group1 pins out 128 lines(8 banks). Group 2 pins out 36 lines(2 banks).

Add DT nodes for each module instance in the main domain. Users should
make sure that correct gpio instance is selected in their pad configuration.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>