riscv: qemu: use device tree passed by prior boot stage

QEMU provides a device tree, which is passed to U-Boot using register
a1. We are now able to directly select the device tree with the
configuration CONFIG_OF_PRIOR_STAGE. Replace the hard-coded address in
qemu-riscv with it.

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/board/emulation/qemu-riscv/qemu-riscv.c b/board/emulation/qemu-riscv/qemu-riscv.c
index 2730a28..2ce093e 100644
--- a/board/emulation/qemu-riscv/qemu-riscv.c
+++ b/board/emulation/qemu-riscv/qemu-riscv.c
@@ -9,8 +9,6 @@
 #include <virtio_types.h>
 #include <virtio.h>
 
-#define MROM_FDT_ADDR	0x1020
-
 int board_init(void)
 {
 	/*
@@ -21,12 +19,3 @@
 
 	return 0;
 }
-
-void *board_fdt_blob_setup(void)
-{
-	/*
-	 * QEMU loads a generated DTB for us immediately
-	 * after the reset vectors in the MROM
-	 */
-	return (void *)MROM_FDT_ADDR;
-}
diff --git a/configs/qemu-riscv32_defconfig b/configs/qemu-riscv32_defconfig
index ff1fb1f..72c54a3 100644
--- a/configs/qemu-riscv32_defconfig
+++ b/configs/qemu-riscv32_defconfig
@@ -3,4 +3,4 @@
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_DISPLAY_CPUINFO=y
 CONFIG_DISPLAY_BOARDINFO=y
-CONFIG_OF_BOARD=y
+CONFIG_OF_PRIOR_STAGE=y
diff --git a/configs/qemu-riscv64_defconfig b/configs/qemu-riscv64_defconfig
index 60b647e..44766c3 100644
--- a/configs/qemu-riscv64_defconfig
+++ b/configs/qemu-riscv64_defconfig
@@ -4,4 +4,4 @@
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_DISPLAY_CPUINFO=y
 CONFIG_DISPLAY_BOARDINFO=y
-CONFIG_OF_BOARD=y
+CONFIG_OF_PRIOR_STAGE=y