MAINTAINERS: add entries for misc. RISC-V SoC drivers and devicetrees

Following some discussion both on & off list, I have volunteered to take
over maintaining the miscellaneous RISC-V devicetrees & soc drivers from
Palmer to ease his load.

So far only SiFive and Microchip have stuff in drivers/soc. For the
former, a SiFive entry exists with a dead GitHub repo - so remove that
to avoid confusion since the patches for drivers/soc & devicetrees will
be routed via my tree & other drivers go through their subsystem trees.
The Microchip directory only contains a RISC-V driver for now, but is
likely to contain drivers for other archs in the future. To that end,
change the PolarFire SoC entry to specifically mention the RISC-V driver
& the new directory level entry does not mention an architecture.

CC: Arnd Bergmann <arnd@arndb.de>
CC: Nicolas Ferre <nicolas.ferre@microchip.com>
CC: Palmer Dabbelt <palmer@dabbelt.com>
Link: https://lore.kernel.org/linux-riscv/mhng-e4210f56-fcc3-4db8-abdb-d43b3ebe695d@palmer-ri-x1c9a/Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20221109212219.1598355-2-conor@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>

MAINTAINERS

@@ -13622,6 +13622,12 @@ S:	Supported
 F:	drivers/misc/atmel-ssc.c
 F:	include/linux/atmel-ssc.h
 
+MICROCHIP SOC DRIVERS
+M:	Conor Dooley <conor@kernel.org>
+S:	Supported
+T:	git https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git/
+F:	drivers/soc/microchip/
+
 MICROCHIP USB251XB DRIVER
 M:	Richard Leitner <richard.leitner@skidata.com>
 L:	linux-usb@vger.kernel.org
@@ -17742,12 +17748,21 @@ F:	drivers/mailbox/mailbox-mpfs.c
 F:	drivers/pci/controller/pcie-microchip-host.c
 F:	drivers/reset/reset-mpfs.c
 F:	drivers/rtc/rtc-mpfs.c
-F:	drivers/soc/microchip/
+F:	drivers/soc/microchip/mpfs-sys-controller.c
 F:	drivers/spi/spi-microchip-core-qspi.c
 F:	drivers/spi/spi-microchip-core.c
 F:	drivers/usb/musb/mpfs.c
 F:	include/soc/microchip/mpfs.h
 
+RISC-V MISC SOC SUPPORT
+M:	Conor Dooley <conor@kernel.org>
+L:	linux-riscv@lists.infradead.org
+S:	Maintained
+Q:	https://patchwork.kernel.org/project/linux-riscv/list/
+T:	git https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git/
+F:	Documentation/devicetree/bindings/riscv/
+F:	arch/riscv/boot/dts/
+
 RNBD BLOCK DRIVERS
 M:	Md. Haris Iqbal <haris.iqbal@ionos.com>
 M:	Jack Wang <jinpu.wang@ionos.com>
@@ -18785,7 +18800,6 @@ M:	Palmer Dabbelt <palmer@dabbelt.com>
 M:	Paul Walmsley <paul.walmsley@sifive.com>
 L:	linux-riscv@lists.infradead.org
 S:	Supported
-T:	git git://github.com/sifive/riscv-linux.git
 N:	sifive
 K:	[^@]sifive
 
@@ -18804,6 +18818,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/dma/sifive,fu540-c000-pdma.yaml
 F:	drivers/dma/sf-pdma/
 
+SIFIVE SOC DRIVERS
+M:	Conor Dooley <conor@kernel.org>
+L:	linux-riscv@lists.infradead.org
+S:	Maintained
+T:	git https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git/
+F:	drivers/soc/sifive/
+
 SILEAD TOUCHSCREEN DRIVER
 M:	Hans de Goede <hdegoede@redhat.com>
 L:	linux-input@vger.kernel.org