DaVinci: remove unneeded #include's

There have accumulated quite a lot of them after the code reorganizations...

In several cases I had to replace #include <linux/dma-mapping.h> which wasn't
needed directly but happened to #include <linux/err.h> which was needed.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>