msm-pcm-q6: Add support for flexible recording period size

- Current implementation supports only fixed buffer size
  of 320 bytes only for audio recording. This results in
  performance overhead for recording at higher sample rate.
- Added support for flexible period size so that user can
  use larger buffers for recording at higher sample rates.

Signed-off-by: SathishKumar Mani<smani@codeaurora.org>
Signed-off-by: Iliyan Malchev <malchev@google.com>

Conflicts:
	sound/soc/msm/msm-pcm-q6.c

Change-Id: Id767a5286a0464608f792b64a788f9cfb7c6ea08
asoc: msm: Add flexible period count to pcm record driver

 In pcm recording, if buffers are not requested from dsp at real
 time then dsp drops the buffers and sends partial buffers. This
 is causing record failures. Pcm record platform driver has two
 periods. If system is loaded, read request will not be at real
 time. Add flexible period count to pcm record platform driver
 so client can configure the period count.

CRs-Fixed: 467746
Signed-off-by: Krishnankutty Kolathappilly <kkolat@codeaurora.org>

Conflicts:
	sound/soc/msm/msm-pcm-q6.c

Change-Id: I1adb255dc23da0fa873c04d886d4a4bef25a5c32
Defconfig: removing devtmpfs