extcon: Modify the name of EXTCON_USB_HOST connector

This patch renames the EXTCON_USB_HOST by using '-' char because
the name of all external connector use the '-' char instead of '_' char.
- "USB_HOST" -> "USB-HOST"

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
index 768e367..09ac5e7 100644
--- a/drivers/extcon/extcon.c
+++ b/drivers/extcon/extcon.c
@@ -60,7 +60,7 @@
 	[EXTCON_USB_HOST] = {
 		.type = EXTCON_TYPE_USB,
 		.id = EXTCON_USB_HOST,
-		.name = "USB_HOST",
+		.name = "USB-HOST",
 	},
 
 	/* Charging external connector */