qemu: Correct CMD_QFW dependencies in Kconfig

Rather than selecting CMD_QFW, we should make the option itself by
enabled by default on these platforms.  Then in the board-specific
Kconfig we should select the appropriate back-end as needed if the
command is enabled.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/board/emulation/qemu-arm/Kconfig b/board/emulation/qemu-arm/Kconfig
index 09c9541..ac2d078 100644
--- a/board/emulation/qemu-arm/Kconfig
+++ b/board/emulation/qemu-arm/Kconfig
@@ -5,8 +5,7 @@
 
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
-	select CMD_QFW
-	select QFW_MMIO
+	select QFW_MMIO if CMD_QFW
 	imply VIRTIO_MMIO
 	imply VIRTIO_PCI
 	imply VIRTIO_NET