* Handle interrupts better

Currently the interrupt handling uses an unusual design employing a kfifo to
transfer irq status to irq thread. This was done as a work around for dropped
interrupts seen with IRQF_ONESHOT based handling.

This needs further investigation and fixing properly, with the aid of
C&M.

* power management handling - add (runtime_)suspen/resume cb where the clock is enabled

* revise logic of wave5_vpu_(dec/enc)_register_framebuffer

* check if the  normal kernel endianness/__swab32 routines are sufficient. (instead of the ones
  implemented in the driver)

* Adjust STREAMON routine for the stateful decoder to adhere to the API, which
  declares that STREAMON can be called before source buffers have been queued.
