arm/km: rename mgcoge2un to mgcoge3un

The mgcoge2un target was only an intermediate step to mgcoge3un.
For this reason the mgcoge2un support was moved to mgcoge3un,
because it isn't needed to support both targets.

We add the BootROM init file for the mgcoge3un memphis RAM.

We also move the suen3 and suen8 boards into the correct category
in the MAINTAINERS file.

Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Acked-by: Heiko Schocher <hs@denx.de>
cc: Wolfgang Denk <wd@denx.de>
cc: Detlev Zundel <dzu@denx.de>
cc: Prafulla Wadaskar <prafulla@marvell.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 30c327b..9660459 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -430,13 +430,10 @@
 	kmsupx5		MPC8321
 	mgcoge		MPC8247
 	mgcoge3ne	MPC8247
-	mgcoge2un	ARM926EJS (Kirkwood SoC)
 	mucmc52		MPC5200
 	muas3001	MPC8270
 	municse		MPC5200
 	sc3		PPC405GP
-	suen3		ARM926EJS (Kirkwood SoC)
-	suen8		ARM926EJS (Kirkwood SoC)
 	suvd3		MPC8321
 	tuda1		MPC8321
 	tuxa1		MPC8321
@@ -820,6 +817,9 @@
 Heiko Schocher <hs@denx.de>
 
 	magnesium	i.MX27
+	mgcoge3un	ARM926EJS (Kirkwood SoC)
+	suen3		ARM926EJS (Kirkwood SoC)
+	suen8		ARM926EJS (Kirkwood SoC)
 
 Robert Schwebel <r.schwebel@pengutronix.de>