x86 32-bit boot: rename bt_ioremap() to early_ioremap()

This patch renames bt_ioremap to early_ioremap, which is used in
x86_64. This makes it easier to merge i386 and x86_64 usage.

[ mingo@elte.hu: fix ]

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/mm/init_32.c

@@ -429,11 +429,11 @@ static void __init pagetable_init (void)
 	 * Fixed mappings, only the page table structure has to be
 	 * created - mappings will be set by set_fixmap():
 	 */
-	bt_ioremap_clear();
+	early_ioremap_clear();
 	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 	end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
 	page_table_range_init(vaddr, end, pgd_base);
-	bt_ioremap_reset();
+	early_ioremap_reset();
 
 	permanent_kmaps_init(pgd_base);