igep00x0: Remove IGEP0020_NAND BOARD entry from MAINTAINERS

Boards with NAND and OneNAND are supported by single configuration,
thus remove now obsolete IGEP0020_NAND BOARD entry.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>

board/isee/igep00x0/MAINTAINERS

@@ -6,9 +6,3 @@ F:	include/configs/omap3_igep00x0.h
 F:	configs/igep0020_defconfig
 F:	configs/igep0030_defconfig
 F:	configs/igep0032_defconfig
-
-IGEP0020_NAND BOARD
-#M:	-
-S:	Maintained
-F:	configs/igep0020_nand_defconfig
-F:	configs/igep0030_nand_defconfig