MAINTAINERS: update riscv/microchip entry

Update the RISC-V/Microchip entry by adding the microchip dts
directory and myself as maintainer

Reviewed-by: Lewis Hanly <lewis.hanly@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

MAINTAINERS

@@ -16575,8 +16575,10 @@ K:	riscv
 
 RISC-V/MICROCHIP POLARFIRE SOC SUPPORT
 M:	Lewis Hanly <lewis.hanly@microchip.com>
+M:	Conor Dooley <conor.dooley@microchip.com>
 L:	linux-riscv@lists.infradead.org
 S:	Supported
+F:	arch/riscv/boot/dts/microchip/
 F:	drivers/mailbox/mailbox-mpfs.c
 F:	drivers/soc/microchip/
 F:	include/soc/microchip/mpfs.h