ASoC: SDCA: fix HID dependency

It is not possible to enable SND_SOC_SDCA_HID when SND_SOC_SDCA is built-in
but HID is in a loadable module, as that results in a link failure:

x86_64-linux-ld: sound/soc/sdca/sdca_functions.o: in function `find_sdca_entity_hide':
sdca_functions.c:(.text+0x25b): undefined reference to `sdca_add_hid_device'

Change SND_SOC_SDCA_HID into a 'bool' option that can only be enabled
if this results in a working build, and change the Makefile so this driver
is a loadable module if possible.

Fixes: ac55801 ("ASoC: SDCA: add a HID device for HIDE entity")
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20250709152430.1498427-1-arnd@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: arndb

sound/soc/sdca/Kconfig

@@ -12,8 +12,9 @@ config SND_SOC_SDCA_OPTIONAL
 	def_tristate SND_SOC_SDCA || !SND_SOC_SDCA
 
 config SND_SOC_SDCA_HID
-	tristate "SDCA HID support"
-	depends on SND_SOC_SDCA && HID
+	bool "SDCA HID support"
+	depends on SND_SOC_SDCA
+	depends on HID=y || HID=SND_SOC_SDCA
 
 config SND_SOC_SDCA_IRQ
 	tristate

sound/soc/sdca/Makefile

@@ -5,5 +5,7 @@ snd-soc-sdca-hid-y := sdca_hid.o
 snd-soc-sdca-irq-y := sdca_interrupts.o
 
 obj-$(CONFIG_SND_SOC_SDCA)	+= snd-soc-sdca.o
-obj-$(CONFIG_SND_SOC_SDCA_HID)	+= snd-soc-sdca-hid.o
+ifdef CONFIG_SND_SOC_SDCA_HID
+obj-$(CONFIG_SND_SOC_SDCA)	+= snd-soc-sdca-hid.o
+endif
 obj-$(CONFIG_SND_SOC_SDCA_IRQ)	+= snd-soc-sdca-irq.o