sh: remove support for sh7300 and solution engine 7300

This patch removes old dead code:
- kill off sh7300 cpu support
- get rid of broken solution engine 7300 board support

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/processor.h b/include/asm-sh/processor.h
index 7969d3a..26d5217 100644
--- a/include/asm-sh/processor.h
+++ b/include/asm-sh/processor.h
@@ -45,7 +45,7 @@
 	CPU_SH7705, CPU_SH7706, CPU_SH7707,
 	CPU_SH7708, CPU_SH7708S, CPU_SH7708R,
 	CPU_SH7709, CPU_SH7709A, CPU_SH7710, CPU_SH7712,
-	CPU_SH7729, CPU_SH7300,
+	CPU_SH7729,
 
 	/* SH-4 types */
 	CPU_SH7750, CPU_SH7750S, CPU_SH7750R, CPU_SH7751, CPU_SH7751R,