defconfig: Add a config for AM43xx secure part

Adds a new defconfig file for the AM43xx secure device.
This is the same as for the non-secure part, except for:
	CONFIG_TI_SECURE_DEVICE option set to 'y'
	CONFIG_ISW_ENTRY_ADDR updated for secure images.

Signed-off-by: Daniel Allred <d-allred@ti.com>
Signed-off-by: Madan Srinivas <madans@ti.com>

Reviewed-by: Tom Rini <trini@konsulko.com>

configs/am437x_hs_evm_defconfig

+CONFIG_ARM=y
+CONFIG_AM43XX=y
+CONFIG_TI_SECURE_DEVICE=y
+CONFIG_TARGET_AM43XX_EVM=y
+CONFIG_DM_SERIAL=y
+CONFIG_DM_GPIO=y
+CONFIG_SPL_STACK_R_ADDR=0x82000000
+# Device tree file can be same on HS evm
+CONFIG_DEFAULT_DEVICE_TREE="am437x-gp-evm"
+CONFIG_SPL=y
+CONFIG_ISW_ENTRY_ADDR=0x40302ae0
+CONFIG_SPL_STACK_R=y
+CONFIG_SYS_EXTRA_OPTIONS="CONS_INDEX=1"
+CONFIG_HUSH_PARSER=y
+CONFIG_CMD_BOOTZ=y
+# CONFIG_CMD_IMLS is not set
+CONFIG_CMD_ASKENV=y
+# CONFIG_CMD_FLASH is not set
+CONFIG_CMD_MMC=y
+CONFIG_CMD_SF=y
+CONFIG_CMD_SPI=y
+CONFIG_CMD_I2C=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_DFU=y
+CONFIG_CMD_GPIO=y
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_MII=y
+CONFIG_CMD_PING=y
+CONFIG_CMD_EXT2=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_EXT4_WRITE=y
+CONFIG_CMD_FAT=y
+CONFIG_CMD_FS_GENERIC=y
+CONFIG_OF_CONTROL=y
+CONFIG_DM=y
+CONFIG_DM_MMC=y
+CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_MACRONIX=y
+CONFIG_SYS_NS16550=y
+CONFIG_TI_QSPI=y
+CONFIG_TIMER=y
+CONFIG_OMAP_TIMER=y
+CONFIG_USB=y
+CONFIG_USB_DWC3=y
+CONFIG_USB_DWC3_GADGET=y
+CONFIG_USB_DWC3_OMAP=y
+CONFIG_USB_DWC3_PHY_OMAP=y
+CONFIG_USB_GADGET=y
+CONFIG_USB_GADGET_DOWNLOAD=y
+CONFIG_G_DNL_MANUFACTURER="Texas Instruments"
+CONFIG_G_DNL_VENDOR_NUM=0x0403
+CONFIG_G_DNL_PRODUCT_NUM=0xbd00