RISC-V: Add kconfig option for QEMU virt machine

We add kconfig option for QEMU virt machine and select all
required VIRTIO drivers using this kconfig option.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

arch/riscv/Kconfig.socs

@@ -10,4 +10,24 @@ config SOC_SIFIVE
 	help
 	  This enables support for SiFive SoC platform hardware.
 
+config SOC_VIRT
+       bool "QEMU Virt Machine"
+       select VIRTIO_PCI
+       select VIRTIO_BALLOON
+       select VIRTIO_MMIO
+       select VIRTIO_CONSOLE
+       select VIRTIO_NET
+       select NET_9P_VIRTIO
+       select VIRTIO_BLK
+       select SCSI_VIRTIO
+       select DRM_VIRTIO_GPU
+       select HW_RANDOM_VIRTIO
+       select RPMSG_CHAR
+       select RPMSG_VIRTIO
+       select CRYPTO_DEV_VIRTIO
+       select VIRTIO_INPUT
+       select SIFIVE_PLIC
+       help
+         This enables support for QEMU Virt Machine.
+
 endmenu