Blackfin Serial Driver: Use timer to poll CTS PIN instead of workqueue.

This allows other threads to run when the serial driver polls the CTS
PIN in a loop.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

diff --git a/include/asm-blackfin/mach-bf533/bfin_serial_5xx.h b/include/asm-blackfin/mach-bf533/bfin_serial_5xx.h
index e924569..ebf592b 100644
--- a/include/asm-blackfin/mach-bf533/bfin_serial_5xx.h
+++ b/include/asm-blackfin/mach-bf533/bfin_serial_5xx.h
@@ -88,7 +88,7 @@
 # endif
 #endif
 #ifdef CONFIG_SERIAL_BFIN_CTSRTS
-	struct work_struct 	cts_workqueue;
+	struct timer_list       cts_timer;
 	int			cts_pin;
 	int			rts_pin;
 #endif