ASoC: img: Imagination Technologies sound should depend on MIPS

Before, all Imagination sound symbols were gated by the SND_SOC_IMG
symbol, offering the user a simple option to hide them all. After the
removal of this gate symbol, all symbols are exposed to the user, even
when configuring a kernel for a non-Imagination platform.
Fix this by adding a dependency on MIPS, to prevent asking the user
about these drivers when configuring a kernel for a different
architecture.

Fixes: b13f7eef9ff82e01 ("ASoC: img: Standardize ASoC menu")
Signed-off-by: Geert Uytterhoeven <[e-mail]>
Link: https://patch.msgid.link/24283[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/img/Kconfig

···
 # SPDX-License-Identifier: GPL-2.0-only
 menu "Imagination Technologies"
+	depends on MIPS || COMPILE_TEST
 
 config SND_SOC_IMG_I2S_IN
 	tristate "Imagination I2S Input Device Driver"