examples: use QEMU compatible LOAD_ADDR on RISC-V

On some RISC-V including QEMU $loadaddr is 0x80200000.
For bootelf to work choose a different LOAD_ADDR to which the demo ELF
binary is relocated.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

examples/api/Makefile

@@ -22,6 +22,9 @@ else
 LOAD_ADDR = 0x80200000
 endif
 endif
+ifeq ($(ARCH),riscv)
+LOAD_ADDR = 0x84000000
+endif
 
 # Resulting ELF and binary exectuables will be named demo and demo.bin
 extra-y = demo