PCI: Use dev_info() rather than dev_err() for ROM validation

On AMD GPUs, we use several mechanisms to fetch the VBIOS ROM depending on
the platform.  We try to read the ROM via the ROM BAR and fall back to
other methods in some cases.  This leads to spurious error messages from
the PCI ROM code which are harmless in our case.  This leads to bugs being
filed, etc.  Change these to dev_info() rather than dev_err() to avoid
that.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=198077
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1462438
Link: https://bugs.freedesktop.org/show_bug.cgi?id=98798


Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christian König <christian.koenig@amd.com>