vexpress64: Correct CONFIG symbol logic around device tree passage

When we don't have BLOBLIST_PASSAGE_MANDATORY enabled, then we're being
passed the device tree in some other manner, via OF_HAS_PRIOR_STAGE.
Correct our logic around which symbols are used to guard what is
generated / used and when.

Signed-off-by: Tom Rini <trini@konsulko.com>
---
Cc: David Feng <fenghua@phytium.com.cn>
Cc: Linus Walleij <linusw@kernel.org>
Cc: Peter Hoyes <Peter.Hoyes@arm.com>
Cc: Raymond Mao <raymondmaoca@gmail.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>

board/armltd/vexpress64/Kconfig

@@ -31,7 +31,7 @@ choice
 config TARGET_VEXPRESS64_BASE_FVP
 	bool "Support Versatile Express ARMv8a FVP BASE model"
 	select VEXPRESS64_BASE_MODEL
-	imply OF_HAS_PRIOR_STAGE if !BLOBLIST
+	imply OF_HAS_PRIOR_STAGE
 
 config TARGET_VEXPRESS64_BASER_FVP
 	bool "Support Versatile Express ARMv8r64 FVP BASE model"

board/armltd/vexpress64/Makefile

@@ -5,6 +5,8 @@
 
 obj-y	:= vexpress64.o
 
+ifeq ($(CONFIG_BLOBLIST_PASSAGE_MANDATORY),)
 obj-$(CONFIG_OF_HAS_PRIOR_STAGE)	+= lowlevel_init.o
+endif
 
 obj-$(CONFIG_TARGET_VEXPRESS64_JUNO)	+= pcie.o

board/armltd/vexpress64/vexpress64.c

@@ -97,7 +97,7 @@ int dram_init_banksize(void)
  * Push the variable into the .data section so that it
  * does not get cleared later.
  */
-#ifdef CONFIG_OF_HAS_PRIOR_STAGE
+#ifndef CONFIG_BLOBLIST_PASSAGE_MANDATORY
 unsigned long __section(".data") prior_stage_fdt_address[2];
 #endif
 
@@ -150,7 +150,7 @@ static phys_addr_t find_dtb_in_nor_flash(const char *partname)
 }
 #endif
 
-#ifdef CONFIG_OF_HAS_PRIOR_STAGE
+#ifndef CONFIG_BLOBLIST_PASSAGE_MANDATORY
 /*
  * Filter for a valid DTB, as TF-A happens to provide a pointer to some
  * data structure using the DTB format, which we cannot use.