Rename the ABI struct and type because they are for configuring physical
DAIs, not only backend DAIs since users may not need DPCM:
- Rename struct snd_soc_tplg_be_dai to snd_soc_tplg_dai.
- Rename type SND_SOC_TPLG_TYPE_BE_DAI to SND_SOC_TPLG_TYPE_DAI.

This code refactoring is backward compatible because:
- Both layout of the struct and type value has no change. Kernel can
  find the same type value and map to same data layout.
- This struct is not in ABI v4 at all. Now the user space uses ABI v4.
Signed-off-by: Mengdong Lin <mengdong.lin@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>