powerpc/eeh: Use eeh_unfreeze_pe()

The patch uses eeh_unfreeze_pe() to replace the logic clearing
frozen IO and DMA, in order to simplify the code.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --cc arch/powerpc/kernel/eeh.c
Simple merge

diff --cc arch/powerpc/kernel/eeh_driver.c
Simple merge

diff --cc arch/powerpc/kernel/eeh_sysfs.c
Simple merge