MAKEALL: remove obsolete at91rm9200 soc

Since complete at91rm9200 SoC device was droped (due to replacement with
common at91 code) this parameter can safely be removed.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/MAKEALL b/MAKEALL
index 266e231..2f4eeb7 100755
--- a/MAKEALL
+++ b/MAKEALL
@@ -444,7 +444,6 @@
 #########################################################################
 
 LIST_at91="$(boards_by_soc at91)\
-	$(boards_by_soc at91rm9200)\
 	at91sam9260ek		\
 	at91sam9261ek		\
 	at91sam9263ek		\