mb/emulation/qemu-riscv: Select DRIVERS_EMULATION_QEMU_FW_CFG

This patch also provides valid 'io_port_mmio_base', which is the addr of
VIRT_FW_CFG device @0x1010_0000 used to convey ACPI & SMBIOS info.

TEST=build and run successfully on QEMU rvvirt machine.

Change-Id: I3cfd3020f1edacbc647188ab232c0a35dbd71f74
Signed-off-by: Ziang Wang <wangziang.ok@bytedance.com>
Signed-off-by: Dong Wei <weidong.wd@bytedance.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/89344
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>

src/mainboard/emulation/qemu-riscv/Kconfig

@@ -37,6 +37,7 @@ config BOARD_SPECIFIC_OPTIONS
 	select ARCH_RAMSTAGE_RISCV
 	select RISCV_USE_ARCH_TIMER
 	select FLATTENED_DEVICE_TREE
+	select DRIVERS_EMULATION_QEMU_FW_CFG
 
 config MEMLAYOUT_LD_FILE
 	string

src/mainboard/emulation/qemu-riscv/Makefile.mk

@@ -5,6 +5,7 @@ bootblock-y += uart.c
 bootblock-y += rom_media.c
 bootblock-y += clint.c
 bootblock-y += smp.c
+bootblock-y += mmio.c
 
 romstage-y += cbmem.c
 romstage-y += romstage.c
@@ -12,6 +13,7 @@ romstage-y += uart.c
 romstage-y += rom_media.c
 romstage-y += clint.c
 romstage-y += smp.c
+romstage-y += mmio.c
 
 ramstage-y += mainboard.c
 ramstage-y += uart.c
@@ -20,5 +22,6 @@ ramstage-y += clint.c
 ramstage-y += cbmem.c
 ramstage-y += chip.c
 ramstage-y += smp.c
+ramstage-y += mmio.c
 
 CPPFLAGS_common += -I$(src)/mainboard/$(MAINBOARDDIR)/include

src/mainboard/emulation/qemu-riscv/include/mainboard/addressmap.h

@@ -4,5 +4,6 @@
 #define QEMU_VIRT_PLIC		0x0c000000
 #define QEMU_VIRT_UART0		0x10000000
 #define QEMU_VIRT_VIRTIO	0x10001000
+#define QEMU_VIRT_FW_CFG	0x10100000
 #define QEMU_VIRT_FLASH		0x20000000
 #define QEMU_VIRT_DRAM		0x80000000

src/mainboard/emulation/qemu-riscv/mmio.c

@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <types.h>
+#include <mainboard/addressmap.h>
+
+uintptr_t io_port_mmio_base = QEMU_VIRT_FW_CFG;