ASoC: Intel: Skylake: Add more SSP DAIs

The Broxton-P platform has 6 SSPs so we need to add ssp2 thru
ssp5 to DAI list for the driver.

Signed-off-by: Pardha Saradhi K <pardha.saradhi.kesapragada@intel.com>
Signed-off-by: Ramesh Babu <ramesh.babu@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>