sh: Kill off dead SH7604 support.

This was added during 2.5.x, but was never moved along. This
can easily be resurrected if someone has one they wish to work
with, but it's not worth keeping around in its current form.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

include/asm-sh/processor.h

@@ -36,7 +36,7 @@
  */
 enum cpu_type {
 	/* SH-2 types */
-	CPU_SH7604, CPU_SH7619,
+	CPU_SH7619,
 
 	/* SH-2A types */
 	CPU_SH7206,