arch, board: squash lines for immediate return

Remove unneeded variables and assignments.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Minkyu Kang <mk7.kang@samsung.com>
Reviewed-by: Angelo Dureghello <angelo@sysam.it>
diff --git a/arch/arm/cpu/sa1100/timer.c b/arch/arm/cpu/sa1100/timer.c
index 0a0006b..90e2128 100644
--- a/arch/arm/cpu/sa1100/timer.c
+++ b/arch/arm/cpu/sa1100/timer.c
@@ -66,8 +66,5 @@
  */
 ulong get_tbclk (void)
 {
-	ulong tbclk;
-
-	tbclk = CONFIG_SYS_HZ;
-	return tbclk;
+	return CONFIG_SYS_HZ;
 }