usb: gadget: Make g_dnl USB settings common

The g_dnl USB settings for the vendor ID, product ID and manufacturer are
actually common settings that can and should be shared by all the gadgets.

Make them common by renaming them, and convert all the users.

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
diff --git a/configs/nitrogen6dl_defconfig b/configs/nitrogen6dl_defconfig
index 30046e3..1803bdb 100644
--- a/configs/nitrogen6dl_defconfig
+++ b/configs/nitrogen6dl_defconfig
@@ -46,11 +46,11 @@
 CONFIG_USB_KEYBOARD=y
 CONFIG_SYS_USB_EVENT_POLL_VIA_CONTROL_EP=y
 CONFIG_USB_GADGET=y
+CONFIG_USB_GADGET_MANUFACTURER="Boundary"
+CONFIG_USB_GADGET_VENDOR_NUM=0x0525
+CONFIG_USB_GADGET_PRODUCT_NUM=0xa4a5
 CONFIG_CI_UDC=y
 CONFIG_USB_GADGET_DOWNLOAD=y
-CONFIG_G_DNL_MANUFACTURER="Boundary"
-CONFIG_G_DNL_VENDOR_NUM=0x0525
-CONFIG_G_DNL_PRODUCT_NUM=0xa4a5
 CONFIG_USB_ETHER=y
 CONFIG_USB_ETH_CDC=y
 # CONFIG_VIDEO_SW_CURSOR is not set