riscv: dts: microchip: add lsram and fabric dma to mpfs-disco-kit dts

commit 748fb2865659ee21702c1034d6b68f1f6c4c044b from
https://github.com/linux4microchip/linux.git

 linux-6.6-mchp+fpga

The PolarFire SoC Discovery Kit reference design includes an LSRAM and
DMA in the fabric, add these two to the mpfs-disco-kit dts.

Signed-off-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: harish h <harish.h@windriver.com>