ARM: OMAP2/3: sDMA: Correct omap_request_dma_chain(), v2

ARM: OMAP2/3: sDMA: Correct omap_request_dma_chain(), v2

Original OMAP DMA chaining design had chain_id as one of the callback
parameters. Patch 33906cd4869619b8b54fd55079e6bde96f41f6c5 changed it
to use logical channel instead.

Correct the naming for callback to also use logical channel number
instead of the chain_id.

More details are on this email thread:

http://marc.info/?l=linux-omap&m=122961071931459&w=2

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>