configs: rockchip: radxa-cm3-io: drop CONFIG_USB_DWC3_GENERIC

it's not used by rk35xx

Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
diff --git a/configs/radxa-cm3-io-rk3566_defconfig b/configs/radxa-cm3-io-rk3566_defconfig
index 9b99181..1df9cab 100644
--- a/configs/radxa-cm3-io-rk3566_defconfig
+++ b/configs/radxa-cm3-io-rk3566_defconfig
@@ -77,5 +77,4 @@
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_EHCI_GENERIC=y
 CONFIG_USB_DWC3=y
-CONFIG_USB_DWC3_GENERIC=y
 CONFIG_ERRNO_STR=y