samsung-gtexswifi: add new device

Hi gtexswifi boots! but In order for gtexswifi to boot, the DHTB string must be appended to boot.img. like this I think same think valid in gtexslte. and screen looks upside down

device/testing/device-samsung-gtexswifi/00-fbdev-rotate-UD.conf

+Section "Device"
+    Identifier "LCD"
+    Driver "fbdev"
+    Option "Rotate" "UD"
+EndSection