MLK-14445-7 DTS: mx7ulp: Add PTA and PTB two GPIO banks

MLK-14445-7 DTS: mx7ulp: Add PTA and PTB two GPIO banks

PTA and PTB banks are at M4 domain, but some boards like ARM2 use
them for controlling A7 domain modules. So we may need to support
them in GPIO driver.

In the imx_rgpio2p driver, the non-DM driver supports full 6 GPIO
banks, with PTA from index 0. But the DM driver which uses DTB only
have 4 GPIO banks, with PTC from index 0.

This will cause problem when using GPIO. So this patch add PTA and PTB
banks to DTB, and reorder the sequence for gpio with PTA from index 0.
So the non-DM driver and DM driver are aligned.

Signed-off-by: Ye Li <ye.li@nxp.com>