arm64: dts: ti: k3-am62-pocketbeagle2: Add missing cfg for TI IPC Firmware

arm64: dts: ti: k3-am62-pocketbeagle2: Add missing cfg for TI IPC Firmware

The wkup_r5fss0_core0_memory_region is used to store the text/data
sections of the Device Manager (DM) firmware itself and is necessary for
platform boot. Whereas the wkup_r5fss0_core0_dma_memory_region is used
for allocating the Virtio buffers needed for IPC with the DM core which
could be optional. The labels were incorrectly used in the
k3-am62-pocketbeagle2.dts file. Correct the firmware memory region label

Currently, only mailbox node is enabled with FIFO assignment for a
single M4F remote core. Add the missing carveouts for WKUP R5F remote
processor, and enable that by associating to the above carveout and
mailbox. This config aligns with other AM62 boards and can be
refactored out later.

Signed-off-by: Beleswar Padhi <b-padhi@ti.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://patch.msgid.link/20250908142826.1828676-18-b-padhi@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>