riscv: dts: microchip: add mpfs specific macb reset support

The macb on PolarFire SoC has reset support which the generic compatible
does not use. Add the newly introduced MPFS specific compatible as the
primary compatible to avail of this support & wire up the reset to the
clock controllers devicetree entry.

Reviewed-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>