sh: sh4: Move to boards.cfg

Move the sh4 target boards out of the Makefile and into boards.cfg.
And fix sh4 of MAKEALL.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/MAKEALL b/MAKEALL
index 71dcba2..4ae741a 100755
--- a/MAKEALL
+++ b/MAKEALL
@@ -611,24 +611,9 @@
 
 LIST_sh2="$(boards_by_cpu sh2)"
 LIST_sh3="$(boards_by_cpu sh3)"
-
-LIST_sh4="		\
-	ms7750se	\
-	ms7722se	\
-	MigoR		\
-	r7780mp		\
-	r2dplus		\
-	sh7763rdp	\
-	sh7785lcr	\
-	ap325rxa	\
-	espt		\
-"
+LIST_sh4="$(boards_by_cpu sh4)"
 
-LIST_sh="		\
-	${LIST_sh2}	\
-	${LIST_sh3}	\
-	${LIST_sh4}	\
-"
+LIST_sh="$(boards_by_arch sh)"
 
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 ## SPARC Systems