MIPS: ingenic: Use fw_passed_dtb even if CONFIG_BUILTIN_DTB

The fw_passed_dtb is now properly initialized even when
CONFIG_BUILTIN_DTB is used, so there's no need to handle it in any
particular way here.

Note that the behaviour is slightly different, as the previous code used
the built-in Device Tree unconditionally, while now the built-in Device
Tree is only used when the bootloader did not provide one.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/jz4740/setup.c

@@ -67,13 +67,8 @@ static unsigned long __init get_board_mach_type(const void *fdt)
 
 void __init plat_mem_setup(void)
 {
+	void *dtb = (void *)fw_passed_dtb;
 	int offset;
-	void *dtb;
-
-	if (__dtb_start != __dtb_end)
-		dtb = __dtb_start;
-	else
-		dtb = (void *)fw_passed_dtb;
 
 	__dt_setup_arch(dtb);