For PUNIT device, ISPDRIVER_IPC and GTDDRIVER_IPC resources are not
mandatory. So when PMC IPC driver creates a PUNIT device, if these
resources are not available then it creates dummy resource entries for
these missing resources. But during PUNIT device probe, doing ioremap on
these dummy resources generates following warning messages.

intel_punit_ipc: can't request region for resource [mem 0x00000000]
intel_punit_ipc: can't request region for resource [mem 0x00000000]
intel_punit_ipc: can't request region for resource [mem 0x00000000]
intel_punit_ipc: can't request region for resource [mem 0x00000000]

This patch fixes this issue by adding extra check for resource size
before performing ioremap operation.
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>