arm64: configs: Remove obsolete TI config

This config is causing conflicts with how fdtfile variable is
initialized.
For K3 devices, CONFIG_DEFAULT_DEVICE_TREE= "ti/k3-<board>.dtb".
With CONFIG_TI_FDT_FOLDER_PATH also prefixing "ti", fdtfile is then
"ti/ti/k3-<board>.dtb". This variable is updated when fitImage is
booted and fails to boot due to the parsing error "ti/ti/".

Given that there are no other users of this config other than K3 for
now, it is being removed.

Since am64x, j721e and j721s2 also define a DEFAULT_FDT_FILE, update
them to conform to the DEFAULT_DEVICE_TREE standard.

Signed-off-by: Aashvij Shenai <a-shenai@ti.com>
diff --git a/board/beagle/beagleboneai64/beagleboneai64.c b/board/beagle/beagleboneai64/beagleboneai64.c
index 1e43d1c..e8d07f1 100644
--- a/board/beagle/beagleboneai64/beagleboneai64.c
+++ b/board/beagle/beagleboneai64/beagleboneai64.c
@@ -73,8 +73,7 @@
 {
 	char fdtfile[50];
 
-	snprintf(fdtfile, sizeof(fdtfile), "%s/%s.dtb",
-		 CONFIG_TI_FDT_FOLDER_PATH, CONFIG_DEFAULT_DEVICE_TREE);
+	snprintf(fdtfile, sizeof(fdtfile), "%s.dtb", CONFIG_DEFAULT_DEVICE_TREE);
 
 	env_set("fdtfile", fdtfile);
 
diff --git a/board/beagle/beagleplay/beagleplay.c b/board/beagle/beagleplay/beagleplay.c
index a21f09e..fae69b3 100644
--- a/board/beagle/beagleplay/beagleplay.c
+++ b/board/beagle/beagleplay/beagleplay.c
@@ -69,8 +69,7 @@
 {
 	char fdtfile[50];
 
-	snprintf(fdtfile, sizeof(fdtfile), "%s/%s.dtb",
-		 CONFIG_TI_FDT_FOLDER_PATH, CONFIG_DEFAULT_DEVICE_TREE);
+	snprintf(fdtfile, sizeof(fdtfile), "%s.dtb", CONFIG_DEFAULT_DEVICE_TREE);
 
 	env_set("fdtfile", fdtfile);