Add error reporting to of_amba_device_create() so the user knows
when (and why) some device tree nodes fail to initialize.

[ The issue was spotted on Universal C210 board (using revision 0 of
  ARM Exynos4210 SoC) on which initialization was silently failing
  for PL330 MDMA1 device tree node (it was using the wrong addres
  resulting in amba_device_add() returning -ENODEV). ]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>