ARM: P2V: avoid initializers and assembly using PHYS_OFFSET

As PHYS_OFFSET will be becoming a variable, we can't have it used in
initializers nor assembly code.  Replace those in generic code with
a run-time initialization.  Replace those in platform code using the
individual platform specific PLAT_PHYS_OFFSET.

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: David Brown <davidb@codeaurora.org>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/setup.c

@@ -740,7 +740,7 @@ static struct init_tags {
 	{ tag_size(tag_core), ATAG_CORE },
 	{ 1, PAGE_SIZE, 0xff },
 	{ tag_size(tag_mem32), ATAG_MEM },
-	{ MEM_SIZE, PHYS_OFFSET },
+	{ MEM_SIZE },
 	{ 0, ATAG_NONE }
 };
 
@@ -839,6 +839,8 @@ void __init setup_arch(char **cmdline_p)
 	struct machine_desc *mdesc;
 	char *from = default_command_line;
 
+	init_tags.mem.start = PHYS_OFFSET;
+
 	unwind_init();
 
 	setup_processor();