msm: lpm-levels: Apply QoS requests only to relevant cpus.

Use the PM QoS cpu/cupmask variant to provide a mimimum CPU_DMA_LATENCY
for the requesting kernel modules. Kernel modules may specify individual
cpus/cpumask but mostly can set the IRQ affinity for QoS. The PM QoS
framework distils the requirement and can provide the latency
requirement for each cpu or a collection of cpus.

Change-Id: I5f5465653496427d3d40a25ec46570d3c183239e
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>