Handle "efi-app-riscv64" and similar targets in objcopy.

This adds the efi target name handling for riscv64 to objcopy.

binutils:
	* binutils/objcopy.c: add riscv64 handling to
	  convert_efi_target()

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>

binutils/objcopy.c

@@ -5129,6 +5129,11 @@ convert_efi_target (char **targ)
       /* Change aarch64 to aarch64-little.  */
       memcpy (pei + 4 + sizeof ("aarch64") - 1, "-little", sizeof ("-little"));
     }
+  else if (strcmp (efi + 4, "riscv64") == 0)
+    {
+      /* Change riscv64 to riscv64-little.  */
+      memcpy (pei + 4 + sizeof ("riscv64") - 1, "-little", sizeof ("-little"));
+    }
   *targ = pei;
   return subsys;
 }