ASoC: SOF: Kconfig: Make SND_SOC_SOF_HDA_PROBES tristate

ASoC: SOF: Kconfig: Make SND_SOC_SOF_HDA_PROBES tristate

SND_SOC_SOF_HDA_PROBES must be tristate because the code it builds
depends on code that is tristate.

If SND_SOC_SOF_HDA_PROBES is bool it leads to the following build
inconsistency:

SND_SOC_SOF_HDA_COMMON=m
  which selects SND_SOC_SOF_HDA_PROBES
    but since this is a bool SND_SOC_SOF_HDA_PROBES=y

SND_SOC_SOF_HDA_PROBES=y
  selects SND_SOC_SOF_DEBUG_PROBES=y
    so sof-client-probes.c is built into the kernel.

sof-client-probes.c calls functions in sof-client.c, but

SND_SOC_SOF=m
  sof-client.c is built into a loadable module.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220407153813.1231866-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>