Custom waveform with FIFO data samples and play rate setting would be passed down from userspace through custom_data memory in periodic effect data structure. Load the waveform into FIFO memory and play it using FIFO mode. Meanwhile, correct a typo in F_16KHZ definition. Change-Id: I26b78df809efbe398c91c89394152caebafbe1b6 Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>