ASoC: davinci: replace private sram api with genalloc

Removes the DaVinci private SRAM API and replaces it with
the genalloc API. The SRAM gen_pool is passed in pdata since
DaVinci is in the early stages of DT conversion.

[zonque@gmail.com: stub out gen_pool functions for
		   !CONFIG_GENERIC_ALLOCATOR]

Signed-off-by: Matt Porter <mporter@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>