DMA: EDMA: Split out PaRAM set calculations into its own function

PaRAM set calculation is abstracted into its own function to
enable better reuse for other DMA cases. Currently it only
implements the Slave case.

This provides a much cleaner abstraction to the internals of the
PaRAM set. However, any PaRAM attributes that are not common to
all DMA types must be set separately. This function only calculates
the most-common attributes.

Also added comments clarifying A-sync case calculations.

Signed-off-by: Joel Fernandes <joelf@ti.com>
DMA: EDMA: Add support for Cyclic DMA

Using the helper functions we split up from the Slave SG code, we
reuse the same functions to add cyclic support.

Signed-off-by: Joel Fernandes <joelf@ti.com>
Revert "DMA: EDMA: Add support for Cyclic DMA"

This reverts commit fa4a07f49fce3132cd2615312ef8a2892a8a643b.
Revert "DMA: EDMA: Split out PaRAM set calculations into its own function"

This reverts commit 87bf23b8990e42bca3f11f6a55399372ad051fc2.