x86/PCI: Make pci=earlydump output neat

Currently the early dump of PCI configuration space looks quite unhelpful,
e.g.

  [    0.000000]   60:
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]  00
  [    0.000000]

which makes really hard to get anything out of this. Convert the function
to use print_hex_dump() to make output neat.

In the result we will have

  [    0.000000] 00000060: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

which is much, much better.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Ingo Molnar <mingo@kernel.org>