defconfig: keystone2: Enable U-boot runtime DTB detection

Enable various config options to allow U-boot at runtime to select the
proper dtb to use from the list of dtb's within the FIT image.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/k2e_evm_defconfig b/configs/k2e_evm_defconfig
index f09eb84..dccaa09 100644
--- a/configs/k2e_evm_defconfig
+++ b/configs/k2e_evm_defconfig
@@ -43,3 +43,6 @@
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_XHCI_DWC3=y
 CONFIG_USB_STORAGE=y
+CONFIG_DTB_RESELECT=y
+CONFIG_FIT_EMBED=y
+CONFIG_OF_LIST="keystone-k2e-evm"