ASoC: msm: qdsp6v2: Fix read error using mmap

When capture session is started in mmap mode then
read commands are issued to ADSP after close command
is issued. This causes read failure as ADSP will not
process the successive read commands after issuing
close command. This change prevents issuing read
command to ADSP when capture session is not in running
state.

Crs-Fixed: 518008
Change-Id: I780fd42dffcd5ee4c051314aaf5f5b537815d8fe
Signed-off-by: Venkat Sudhir <vsudhir@codeaurora.org>