mx7dsabresd: Fix the boot of a NXP kernel

Booting a NXP kernel with mainline U-boot leads to the following kernel
crash:

caam: probe of 30900000.caam failed with error -11
Unable to handle kernel NULL pointer dereference at virtual address 00000004
pgd = 80004000
[00000004] *pgd=00000000
Internal error: Oops: 805 [#1] PREEMPT SMP ARM

This happens because NXP kernel expects MX7 to boot in secure mode,
so introduce mx7dsabresd_secure_defconfig that selects CONFIG_MX7_SEC
and allows booting a NXP provided kernel successfully.

Signed-off-by: Fabio Estevam <[email protected]>

configs/mx7dsabresd_secure_defconfig

@@ -0,0 +1,38 @@
+CONFIG_ARM=y
+CONFIG_ARCH_MX7=y
+CONFIG_TARGET_MX7DSABRESD=y
+CONFIG_IMX_RDC=y
+CONFIG_IMX_BOOTAUX=y
+CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/mx7dsabresd/imximage.cfg"
+CONFIG_HUSH_PARSER=y
+# CONFIG_CMD_BOOTD is not set
+CONFIG_CMD_BOOTZ=y
+# CONFIG_CMD_IMI is not set
+# CONFIG_CMD_IMLS is not set
+# CONFIG_CMD_XIMG is not set
+# CONFIG_CMD_EXPORTENV is not set
+# CONFIG_CMD_IMPORTENV is not set
+CONFIG_CMD_MEMTEST=y
+CONFIG_CMD_MMC=y
+CONFIG_CMD_I2C=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_DFU=y
+CONFIG_CMD_USB_MASS_STORAGE=y
+CONFIG_CMD_GPIO=y
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_MII=y
+CONFIG_CMD_PING=y
+CONFIG_CMD_CACHE=y
+CONFIG_CMD_EXT2=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_CMD_FAT=y
+CONFIG_USB=y
+CONFIG_USB_GADGET=y
+CONFIG_CI_UDC=y
+CONFIG_USB_GADGET_DOWNLOAD=y
+CONFIG_G_DNL_MANUFACTURER="FSL"
+CONFIG_G_DNL_VENDOR_NUM=0x0525
+CONFIG_G_DNL_PRODUCT_NUM=0xa4a5
+CONFIG_OF_LIBFDT=y
+CONFIG_MX7_SEC=y