ARM: imx: Add MXC_CPU_IMX6ULL and cpu_is_imx6ull

Support for imx6ull is already present but it's based on
of_machine_is_compatible("fsl,imx6ull") checks. Add it to the MXC_CPU_*
enumeration as well.

This also fixes /sys/devices/soc0/soc_id reading "Unknown".

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
diff --git a/arch/arm/mach-imx/cpu.c b/arch/arm/mach-imx/cpu.c
index b3347d3..94906ed 100644
--- a/arch/arm/mach-imx/cpu.c
+++ b/arch/arm/mach-imx/cpu.c
@@ -131,6 +131,9 @@ struct device * __init imx_soc_device_init(void)
 	case MXC_CPU_IMX6UL:
 		soc_id = "i.MX6UL";
 		break;
+	case MXC_CPU_IMX6ULL:
+		soc_id = "i.MX6ULL";
+		break;
 	case MXC_CPU_IMX7D:
 		soc_id = "i.MX7D";
 		break;