imx-common: timer: support i.MX6DQPlus

To i.MX6DQPlus, osc can be choosed as the source of gpt, so
add i.MX6DQPlus support in gpt_has_clk_source_osc.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/imx-common/timer.c b/arch/arm/imx-common/timer.c
index bea17f2..a01590c 100644
--- a/arch/arm/imx-common/timer.c
+++ b/arch/arm/imx-common/timer.c
@@ -44,7 +44,7 @@
 {
 #if defined(CONFIG_MX6)
 	if (((is_mx6dq()) && (soc_rev() > CHIP_REV_1_0)) ||
-	    is_mx6sdl() || is_mx6sx() || is_mx6ul())
+	    is_mx6dqp() || is_mx6sdl() || is_mx6sx() || is_mx6ul())
 		return 1;
 
 	return 0;