ARM: mx6: Only check for 1.2GHz for mx6quad

It is only the mx6quad variant that can run up to 1.2GHz, so add the check
accordingly.

This avoids getting the following warning on a mx6solo:

failed to disable 1.2 GHz OPP
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NShawn Guo <shawn.guo@freescale.com>

arch/arm/mach-imx/mach-imx6q.c

@@ -320,7 +320,7 @@ static void __init imx6q_opp_check_speed_grading(struct device *cpu_dev)
 	val >>= OCOTP_CFG3_SPEED_SHIFT;
 	val &= 0x3;
 
-	if (val != OCOTP_CFG3_SPEED_1P2GHZ)
+	if ((val != OCOTP_CFG3_SPEED_1P2GHZ) && cpu_is_imx6q())
 		if (dev_pm_opp_disable(cpu_dev, 1200000000))
 			pr_warn("failed to disable 1.2 GHz OPP\n");
 	if (val < OCOTP_CFG3_SPEED_996MHZ)