Block interrupts give interrupt on completion of every LLI, which is actually
too much interrupts. This is just not required for current functioning of
dw_dmac.

So, just don't handle them at all.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@linux.intel.com>