MAINTAINERS: Add entry for SPI NAND framework and drivers

In [1] Michael agreed on taking patches for SPI NAND through the RAW
NAND tree. Add a dedicated entry to the MAINTAINERS file which adds
Michael and Dario as maintainers and myself as reviewer.

[1] https://lists.denx.de/pipermail/u-boot/2023-February/508571.html

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Cc: Michael Nazzareno Trimarchi <michael@amarulasolutions.com>
Cc: Tom Rini <trini@konsulko.com>
Link: https://lore.kernel.org/all/20230213094626.50957-1-frieder@fris.de/
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 4c17c6c..d188e9f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1398,6 +1398,14 @@
 F:	drivers/spi/
 F:	include/spi*
 
+SPI NAND
+M:	Dario Binacchi <dario.binacchi@amarulasolutions.com>
+M:	Michael Trimarchi <michael@amarulasolutions.com>
+R:	Frieder Schrempf <frieder.schrempf@kontron.de>
+S:	Maintained
+T:	git https://source.denx.de/u-boot/custodians/u-boot-nand-flash.git
+F:	drivers/mtd/nand/spi/
+
 SPI-NOR
 M:	Jagan Teki <jagan@amarulasolutions.com>
 M:	Vignesh R <vigneshr@ti.com>