verdin-am62: move verdin am62 to OF_UPSTREAM

Move verdin-am62 to OF_UPSTREAM:
- handle the fact that dtbs now have a 'ti/' prefix
- imply OF_UPSTREAM
- remove redundant files from arch/arm/dts leaving only the
  *-u-boot.dtsi files
- update MAINTAINERS file

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Neha Malcom Francis <n-francis@ti.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
diff --git a/arch/arm/dts/k3-am625-verdin-wifi-dev-binman.dtsi b/arch/arm/dts/k3-am625-verdin-wifi-dev-binman.dtsi
index 4e37048..6f58450 100644
--- a/arch/arm/dts/k3-am625-verdin-wifi-dev-binman.dtsi
+++ b/arch/arm/dts/k3-am625-verdin-wifi-dev-binman.dtsi
@@ -140,7 +140,7 @@
 
 #ifdef CONFIG_TARGET_VERDIN_AM62_A53
 
-#define SPL_VERDIN_AM62_DTB "spl/dts/k3-am625-verdin-wifi-dev.dtb"
+#define SPL_VERDIN_AM62_DTB "spl/dts/ti/k3-am625-verdin-wifi-dev.dtb"
 #define VERDIN_AM62_DTB "u-boot.dtb"
 
 &binman {