DMAENGINE: ste_dma40: rewrote LCLA entries allocation code

LLI allocation is now done on job level instead of channel level.
Previously the maximum length of a linked job in hw on a logical
channel was 8, since the LLIs where evenly divided. Now only
executing jobs have allocated LLIs which increase the length to
a maximum of 64 links in HW.

Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>