Permit ALSA to run without hardware interrupts from the audio interface.
Instead, ALSA will use a kernel timer to decide when to check the buffer
state, resulting in a lighter workload for the CPU.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NMark Brown <broonie@linaro.org>