lib/ioremap.c should #include <linux/io.h>

Every file should include the headers containing the prototypes for its global
functions (in this case ioremap_page_range()).

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>