iidc/ice/irdma: Rename IDC header file

iidc/ice/irdma: Rename IDC header file

To prepare for the IDC upgrade to support different CORE
PCI drivers, rename header file from iidc.h to iidc_rdma.h
since this files functionality is specifically for RDMA support.

Use net/dscp.h include in irdma osdep.h and DSCP_MAX type.h,
instead of iidc header and define.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Signed-off-by: Tatyana Nikolova <tatyana.e.nikolova@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>