arm64: defconfig: add virtio support for running as a kvm guest

When running as a kvm guest on a para-virtualised platform, it is useful
to have virtio implementations of console, 9pfs and network.

This adds these options to the arm64 defconfig, so we can easily run a
defconfig kernel build as both host and as a kvm guest.
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/configs/defconfig

@@ -52,6 +52,8 @@ CONFIG_IP_PNP_BOOTP=y
 # CONFIG_INET_LRO is not set
 # CONFIG_IPV6 is not set
 # CONFIG_WIRELESS is not set
+CONFIG_NET_9P=y
+CONFIG_NET_9P_VIRTIO=y
 CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
 CONFIG_DEVTMPFS=y
 CONFIG_DMA_CMA=y
@@ -65,6 +67,7 @@ CONFIG_PATA_PLATFORM=y
 CONFIG_PATA_OF_PLATFORM=y
 CONFIG_NETDEVICES=y
 CONFIG_TUN=y
+CONFIG_VIRTIO_NET=y
 CONFIG_SMC91X=y
 CONFIG_SMSC911X=y
 # CONFIG_WLAN is not set
@@ -76,6 +79,7 @@ CONFIG_SERIAL_8250_CONSOLE=y
 CONFIG_SERIAL_AMBA_PL011=y
 CONFIG_SERIAL_AMBA_PL011_CONSOLE=y
 CONFIG_SERIAL_OF_PLATFORM=y
+CONFIG_VIRTIO_CONSOLE=y
 # CONFIG_HW_RANDOM is not set
 # CONFIG_HWMON is not set
 CONFIG_REGULATOR=y
@@ -90,6 +94,7 @@ CONFIG_USB_ISP1760_HCD=y
 CONFIG_USB_STORAGE=y
 CONFIG_MMC=y
 CONFIG_MMC_ARMMMCI=y
+CONFIG_VIRTIO_BALLOON=y
 CONFIG_VIRTIO_MMIO=y
 # CONFIG_IOMMU_SUPPORT is not set
 CONFIG_EXT2_FS=y
@@ -107,6 +112,7 @@ CONFIG_HUGETLBFS=y
 # CONFIG_MISC_FILESYSTEMS is not set
 CONFIG_NFS_FS=y
 CONFIG_ROOT_NFS=y
+CONFIG_9P_FS=y
 CONFIG_NLS_CODEPAGE_437=y
 CONFIG_NLS_ISO8859_1=y
 CONFIG_VIRTUALIZATION=y