arm: dts: keystone: Move to OF_UPSTREAM

Enable OF_UPSTREAM for Keystone boards. Remove DT files that
are now available in dts/upstream.

Signed-off-by: Andrew Davis <afd@ti.com>
Acked-by: Neha Malcom Francis <n-francis@ti.com>
diff --git a/configs/k2l_hs_evm_defconfig b/configs/k2l_hs_evm_defconfig
index c874349..5496049 100644
--- a/configs/k2l_hs_evm_defconfig
+++ b/configs/k2l_hs_evm_defconfig
@@ -15,7 +15,7 @@
 CONFIG_SF_DEFAULT_SPEED=30000000
 CONFIG_ENV_SIZE=0x40000
 CONFIG_ENV_OFFSET=0x100000
-CONFIG_DEFAULT_DEVICE_TREE="keystone-k2l-evm"
+CONFIG_DEFAULT_DEVICE_TREE="ti/keystone/keystone-k2l-evm"
 CONFIG_TIMESTAMP=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_USE_BOOTCOMMAND=y
@@ -78,3 +78,4 @@
 CONFIG_USB_DWC3=y
 CONFIG_USB_DWC3_GENERIC=y
 CONFIG_USB_STORAGE=y
+CONFIG_OF_UPSTREAM=y