riscv: do not use ram_size global

Use the machine properties instead.

Cc: Alistair Francis <Alistair.Francis@wdc.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Author: bonzini

hw/riscv/boot.c

@@ -120,7 +120,8 @@ target_ulong riscv_load_firmware(const char *firmware_filename,
     }
 
     firmware_size = load_image_targphys_as(firmware_filename,
-                                           firmware_load_addr, ram_size, NULL);
+                                           firmware_load_addr,
+                                           current_machine->ram_size, NULL);
 
     if (firmware_size > 0) {
         return firmware_load_addr + firmware_size;
@@ -148,7 +149,7 @@ target_ulong riscv_load_kernel(const char *kernel_filename,
     }
 
     if (load_image_targphys_as(kernel_filename, kernel_start_addr,
-                               ram_size, NULL) > 0) {
+                               current_machine->ram_size, NULL) > 0) {
         return kernel_start_addr;
     }