Since we will have not only DT cases in future let's rename DT related methods
to reflect their belonging.

The rename was done as follows:
	struct dw_dma_filter_args	-> struct dw_dma_of_filter_args
	dw_dma_generic_filter()		-> dw_dma_of_filter()
	dw_dma_xlate()			-> dw_dma_of_xlate()
	dw_dma_id_table			-> dw_dma_of_id_table

There is no functional change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>