ASoC: SOF: Intel: soundwire: fix select/depend unmet dependencies

The LKP bot reports the following issue:

WARNING: unmet direct dependencies detected for SOUNDWIRE_INTEL
  Depends on [m]: SOUNDWIRE [=m] && ACPI [=y] && SND_SOC [=y]
  Selected by [y]:
  - SND_SOC_SOF_INTEL_SOUNDWIRE [=y] && SOUND [=y] && !UML &&
  SND [=y] && SND_SOC [=y] && SND_SOC_SOF_TOPLEVEL [=y] &&
  SND_SOC_SOF_INTEL_TOPLEVEL [=y] && SND_SOC_SOF_INTEL_PCI [=y]

This comes from having tristates being configured independently, when
in practice the CONFIG_SOUNDWIRE needs to be aligned with the SOF
choices: when the SOF code is compiled as built-in, the
CONFIG_SOUNDWIRE also needs to be 'y'.

The easiest fix is to replace the 'depends' with a 'select' and have a
single user selection to activate SoundWire on Intel platforms. This
still allows regmap to be compiled independently as a module.

This is just a temporary fix, the select/depend usage will be
revisited and the SOF Kconfig re-organized, as suggested by Arnd
Bergman.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: a115ab9b ('ASoC: SOF: Intel: add build support for SoundWire')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210122005725.94163-2-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/intel/Kconfig

@@ -355,7 +355,7 @@ config SND_SOC_SOF_HDA
 
 config SND_SOC_SOF_INTEL_SOUNDWIRE_LINK
 	bool "SOF support for SoundWire"
-	depends on SOUNDWIRE && ACPI
+	depends on ACPI
 	help
 	  This adds support for SoundWire with Sound Open Firmware
 	  for Intel(R) platforms.
@@ -371,6 +371,7 @@ config SND_SOC_SOF_INTEL_SOUNDWIRE_LINK_BASELINE
 
 config SND_SOC_SOF_INTEL_SOUNDWIRE
 	tristate
+	select SOUNDWIRE
 	select SOUNDWIRE_INTEL
 	help
 	  This option is not user-selectable but automagically handled by