pci: Move PCI VGA to pci.mak

Every platform that supports PCI can also spawn the Bochs VGA PCI adapter. Move
it to pci.mak to enable it for everyone.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/default-configs/pci.mak b/default-configs/pci.mak
index 030cdc7..bea6b01 100644
--- a/default-configs/pci.mak
+++ b/default-configs/pci.mak
@@ -33,3 +33,5 @@
 CONFIG_SD=y
 CONFIG_SDHCI=y
 CONFIG_EDU=y
+CONFIG_VGA=y
+CONFIG_VGA_PCI=y