ASoC: rt5677: add build dependency to spi

Since 9cb715a9d4c the codec has a hardcoded dependency to spi.
Add this dependency to Kconfig. It fixes buildbot compilation failure:

   sound/built-in.o: In function `spi_write':
>> rt5677-spi.c:(.text+0x8265f): undefined reference to `spi_sync'
   sound/built-in.o: In function `rt5677_spi_driver_init':
>> rt5677-spi.c:(.init.text+0x17db): undefined reference to `spi_register_driver'

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>