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/arch/sh/kernel/timers/timer-tmu.c b/arch/sh/kernel/timers/timer-tmu.c
index 7aca37d..8a545d5 100644
--- a/arch/sh/kernel/timers/timer-tmu.c
+++ b/arch/sh/kernel/timers/timer-tmu.c
@@ -173,8 +173,7 @@
 
 	tmu_timer_stop();
 
-#if !defined(CONFIG_CPU_SUBTYPE_SH7300) && \
-    !defined(CONFIG_CPU_SUBTYPE_SH7760) && \
+#if !defined(CONFIG_CPU_SUBTYPE_SH7760) && \
     !defined(CONFIG_CPU_SUBTYPE_SH7785) && \
     !defined(CONFIG_CPU_SUBTYPE_SHX3)
 	ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);