sh: Make sure rte delay slots are nopped out on all parts.

Future SH parts do not support any instruction but a nop in the rte delay
slot, so make the change for all offending parts. SH-5 is excluded from
this, and already has its own set of restrictions with regards to rte
delay slot handling.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/sh2/entry.S

@@ -227,8 +227,9 @@ ENTRY(sh_bios_handler)
 	mov.l	@r15+, r14
 	add	#8,r15
 	lds.l	@r15+, pr
+	mov.l	@r15+,r15
 	rte
-	 mov.l	@r15+,r15
+	 nop
 	.align	2
 1:	.long	gdb_vbr_vector
 #endif /* CONFIG_SH_STANDARD_BIOS */

arch/sh/kernel/cpu/sh2a/entry.S

@@ -176,8 +176,9 @@ ENTRY(sh_bios_handler)
 	movml.l	@r15+,r14
 	add	#8,r15
 	lds.l	@r15+, pr
+	mov.l	@r15+,r15
 	rte
-	 mov.l	@r15+,r15
+	 nop
 	.align	2
 1:	.long	gdb_vbr_vector
 #endif /* CONFIG_SH_STANDARD_BIOS */