ARM: multi_v7_defconfig: Enable i.MX7ULP SoC

Enable i.MX7ULP SoC which is already supported by mainline kernel.

Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/configs/multi_v7_defconfig

@@ -48,6 +48,7 @@ CONFIG_SOC_IMX6SX=y
 CONFIG_SOC_IMX6UL=y
 CONFIG_SOC_LS1021A=y
 CONFIG_SOC_IMX7D=y
+CONFIG_SOC_IMX7ULP=y
 CONFIG_SOC_VF610=y
 CONFIG_ARCH_KEYSTONE=y
 CONFIG_ARCH_MEDIATEK=y