x86: make c_p_a unconditional in ioremap

Make c_p_a unconditional for ioremap and iounmap. This ensures
complete consistency of the flags which are handed to
ioremap_page_range and the real flags in the mappings.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>