powerpc/fsl_rio: Fix non-standard HID1 register access

Moved setting of RFXE bit so we get machine checks on RIO errors into
cpu_setup so that the RIO code isn't core specific.

Signed-off-by: Shaohui Xie <b21989@freescale.com>
Cc: Li Yang <leoli@freescale.com>
Cc: Roy Zang <tie-fei.zang@freescale.com>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>