Adding Edl button in reboot menu

Edl mode is available only on qualcomm devices and it used to fully
restore the bricked devices. I made the button available only if
TW_HAS_EDL_MODE := true like the download button. I set the edl
button to the right of the download button, so devices can support
edl button and download button. I also added the translation for
all languages.

Change-Id: I69d1058b8c050b722395c7b3da6dce1ccfbe7a91
diff --git a/gui/theme/extra-languages/languages/zh_TW.xml b/gui/theme/extra-languages/languages/zh_TW.xml
index 75c717a..fc80862 100644
--- a/gui/theme/extra-languages/languages/zh_TW.xml
+++ b/gui/theme/extra-languages/languages/zh_TW.xml
@@ -283,6 +283,7 @@
 		<string name="rb_recovery_btn">Recovery</string>
 		<string name="rb_bootloader_btn">Bootloader</string>
 		<string name="rb_download_btn">Download</string>
+		<string name="rb_edl_btn">Edl</string>
 		<string name="turning_off">正在關機…</string>
 		<string name="swipe_power_off">滑動按鈕確認關機</string>
 		<string name="swipe_power_off_s">關機</string>