MAINTAINERS: add the Polarfire SoC's i2c driver

Add the newly added i2c controller driver to the existing entry for
PolarFire SoC.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Link: https://lore.kernel.org/r/20220810140243.2685416-3-conor.dooley@microchip.com'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

MAINTAINERS

@@ -17289,6 +17289,7 @@ F:	Documentation/devicetree/bindings/usb/microchip,mpfs-musb.yaml
 F:	arch/riscv/boot/dts/microchip/
 F:	drivers/char/hw_random/mpfs-rng.c
 F:	drivers/clk/microchip/clk-mpfs.c
+F:	drivers/i2c/busses/i2c-microchip-core.c
 F:	drivers/mailbox/mailbox-mpfs.c
 F:	drivers/pci/controller/pcie-microchip-host.c
 F:	drivers/soc/microchip/