Apply keybow customizations

* Remove precompiled USB ETH device
  * CONFIG_USB_ETH
* Enable USB ConfigFS
  * `CONFIG_USB_CONFIGFS=y`
* Enable various ConfigFS network device drivers
  * `CONFIG_USB_CONFIGFS_NCM=y`
  * `CONFIG_USB_CONFIGFS_ECM=y`
  * `CONFIG_USB_CONFIGFS_RNDIS=y`
* Enable ConfigFS HID device functionality
  * `CONFIG_USB_CONFIGFS_F_HID=y`
* Enable network device bonding
  * `CONFIG_BONDING=y`
* Add libusbgx for USB gadget device tools
  * `BR2_PACKAGE_LIBUSBGX=y`

linux-5.10.defconfig

@@ -78,6 +78,7 @@ CONFIG_BLK_DEV_LOOP=y
 CONFIG_BLK_DEV_RAM=y
 CONFIG_EEPROM_AT24=m
 CONFIG_NETDEVICES=y
+CONFIG_BONDING=y
 CONFIG_WIREGUARD=m
 CONFIG_TUN=m
 # CONFIG_NET_VENDOR_AMAZON is not set
@@ -344,7 +345,12 @@ CONFIG_SND_SIMPLE_CARD=m
 # CONFIG_HID_GENERIC is not set
 CONFIG_USB_DWC2=m
 CONFIG_USB_GADGET=y
-CONFIG_USB_ETH=y
+CONFIG_USB_GADGET_VBUS_DRAW=500
+CONFIG_USB_CONFIGFS=y
+CONFIG_USB_CONFIGFS_NCM=y
+CONFIG_USB_CONFIGFS_ECM=y
+CONFIG_USB_CONFIGFS_RNDIS=y
+CONFIG_USB_CONFIGFS_F_HID=y
 CONFIG_MMC=y
 CONFIG_MMC_BLOCK_MINORS=32
 CONFIG_MMC_BCM2835_MMC=y

nerves_defconfig

@@ -59,6 +59,7 @@ BR2_PACKAGE_RPI_USERLAND=y
 # BR2_PACKAGE_ALSA_LIB_OLD_SYMBOLS is not set
 BR2_PACKAGE_LIBP11=y
 BR2_PACKAGE_UNIXODBC=y
+BR2_PACKAGE_LIBUSBGX=y
 BR2_PACKAGE_LIBMNL=y
 BR2_PACKAGE_WIRELESS_REGDB=y
 BR2_PACKAGE_WPA_SUPPLICANT=y