ASoC: Intel: Skylake: stop probe if HDaudio capabilities don't exist

Check immediately if required HDaudio capabilities can't be found (no
PPCAP or no streams exposed in GCAP), and move all DMA inits after the
error tests.

PPCAP and GCAP are not reliable indicators of DSP presence, but if
they don't exist then the driver will not work.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>