riscv: qemu: Enable usb keyboard as an input device

This brings PCI xHCI support to QEMU RISC-V and uses a usb keyboard
as one of the input devices.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Rick Chen <rick@andestech.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/emulation/qemu-riscv/Kconfig b/board/emulation/qemu-riscv/Kconfig
index 7220c55..b503578 100644
--- a/board/emulation/qemu-riscv/Kconfig
+++ b/board/emulation/qemu-riscv/Kconfig
@@ -76,5 +76,10 @@
 	imply VIDEO_BOCHS
 	imply SYS_WHITE_ON_BLACK
 	imply PRE_CONSOLE_BUFFER
+	imply USB
+	imply USB_XHCI_HCD
+	imply USB_XHCI_PCI
+	imply USB_KEYBOARD
+	imply CMD_USB
 
 endif