topology: pre-process-dai: add support for pcm_caps objects

topology: pre-process-dai: add support for pcm_caps objects

Add support for processing pcm_caps objects.
For ex:

Object.PCM.pcm."0" {
	name	"Port0"
	direction	"duplex"
	Object.Base.fe_dai."Port 0" {}
	Object.PCM.pcm_caps."playback" {
		name "Port0 Playback"
	}
	Object.PCM.pcm_caps."capture" {
		name "Port0 Capture"
	}
}

Would convert into:
SectionPCMCapabilities {
        'Port0 Playback' {
                formats 'S32_LE,S24_LE,S16_LE'
                rate_min 48000
                rate_max 48000
                channels_min 2
                channels_max 2
                periods_min 2
                periods_max 16
                period_size_min 192
                period_size_max 16384
                buffer_size_min 65536
                buffer_size_max 65536
        }
        'Port0 Capture' {
                formats 'S32_LE,S24_LE,S16_LE'
                rate_min 48000
                rate_max 48000
                channels_min 2
                channels_max 2
                periods_min 2
                periods_max 16
                period_size_min 192
                period_size_max 16384
                buffer_size_min 65536
                buffer_size_max 65536
        }
}

and the SectionPCM updated as follows:
SectionPCM {
        Port0 {
                id 0
                dai {
                        'Port 0' {
                                id 0
                        }
                }
                pcm {
                        playback {
                                capabilities 'Port0 Playback'
                        }
                        capture {
                                capabilities 'Port0 Capture'
                        }
                }
        }
}

Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>