arm/dt: consolidate atags setup into setup_machine_atags

In preparation for adding device tree support, this patch consolidates
all of the atag-specific setup into a single function.

v5: - drop double printk("Machine; %s\n", ...); call.
    - leave copying boot_command_line in setup_arch() since it isn't
      atags specific.
v4: - adapt to the removal of lookup_machine_type()
    - break out dump of machine_desc table into dump_machine_table()
      because the device tree probe code will use it.
    - Add for_each_machine_desc() macro

Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
index bf13b81..4764e67 100644
--- a/arch/arm/include/asm/mach/arch.h
+++ b/arch/arm/include/asm/mach/arch.h
@@ -48,6 +48,13 @@
 extern struct machine_desc *machine_desc;
 
 /*
+ * Machine type table - also only accessible during boot
+ */
+extern struct machine_desc __arch_info_begin[], __arch_info_end[];
+#define for_each_machine_desc(p)			\
+	for (p = __arch_info_begin; p < __arch_info_end; p++)
+
+/*
  * Set of macros to define architecture features.  This is built into
  * a table by the linker.
  */