igep00x0: merge igep0020 and igep0030 defconfigs to igep00x0_defconfig

Update igep00x0 code with the following features:
- Add board and revision detection for the boards:
  - IGEP0020-RF
  - IGEP0020-RC
  - IGEP0030-RG
  - IGEP0030-RE
- Merge IGEP0020 and IGEP0030 mux tables
- Add suport to use GPIO_126, GPIO_127 and GPIO_129
- board_name and board_rev environment variables display board and
  revision informations
- Move dtb name selection from code to boot script

Signed-off-by: Pau Pajuelo <ppajuel@gmail.com>
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Tested-by: Pau Pajuelo <ppajuel@gmail.com>
diff --git a/board/isee/igep00x0/MAINTAINERS b/board/isee/igep00x0/MAINTAINERS
index 720ef2a..d75d400 100644
--- a/board/isee/igep00x0/MAINTAINERS
+++ b/board/isee/igep00x0/MAINTAINERS
@@ -3,6 +3,5 @@
 S:	Maintained
 F:	board/isee/igep00x0/
 F:	include/configs/omap3_igep00x0.h
-F:	configs/igep0020_defconfig
-F:	configs/igep0030_defconfig
+F:	configs/igep00x0_defconfig
 F:	configs/igep0032_defconfig