riscv: qemu: define standalone load address

We need to define the standalone load address to use standalone
application on qemu-riscv. Define it and set it equal to
CONFIG_SYS_LOAD_ADDR.

To not overwrite it, change the assigned of CONFIG_STANDALONE_LOAD_ADDR
in arch/riscv/config.mk to a conditional one.

Signed-off-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

arch/riscv/config.mk

@@ -23,7 +23,7 @@ PLATFORM_LDFLAGS	+= -m $(64bit-emul)
 EFI_LDS			:= elf_riscv64_efi.lds
 endif
 
-CONFIG_STANDALONE_LOAD_ADDR = 0x00000000
+CONFIG_STANDALONE_LOAD_ADDR ?= 0x00000000
 
 PLATFORM_CPPFLAGS	+= -ffixed-gp -fpic
 PLATFORM_RELFLAGS	+= -fno-common -gdwarf-2 -ffunction-sections \

include/configs/qemu-riscv.h

@@ -17,6 +17,8 @@
 
 #define CONFIG_SYS_BOOTM_LEN		SZ_16M
 
+#define CONFIG_STANDALONE_LOAD_ADDR	0x80200000
+
 /* Environment options */
 #define CONFIG_ENV_SIZE			SZ_4K