ARM: Enable Trusted Foundations for multiplatform ARM v7

Some 32-bit Tegra devices supported by the multiplatform ARM v7 default
configuration ship with the Trusted Foundations firmware. Enable support
for it by default.
Signed-off-by: NThierry Reding <treding@nvidia.com>

arch/arm/configs/multi_v7_defconfig

@@ -110,6 +110,7 @@ CONFIG_ARM_ZYNQ_CPUIDLE=y
 CONFIG_ARM_EXYNOS_CPUIDLE=y
 CONFIG_KERNEL_MODE_NEON=y
 CONFIG_RASPBERRYPI_FIRMWARE=y
+CONFIG_TRUSTED_FOUNDATIONS=y
 CONFIG_BCM47XX_NVRAM=y
 CONFIG_BCM47XX_SPROM=y
 CONFIG_EFI_VARS=m