serial: sprd: adjust TIMEOUT to a big value

SPRD_TIMEOUT was 256, which is too small to wait until the status
switched to workable in a while loop, so that the earlycon could
not work correctly.
Signed-off-by: NWei Qiao <wei.qiao@spreadtrum.com>
Signed-off-by: NChunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sprd_serial.c

@@ -36,7 +36,7 @@
 #define SPRD_FIFO_SIZE		128
 #define SPRD_DEF_RATE		26000000
 #define SPRD_BAUD_IO_LIMIT	3000000
-#define SPRD_TIMEOUT		256
+#define SPRD_TIMEOUT		256000
 
 /* the offset of serial registers and BITs for them */
 /* data registers */