sh: boards: Use imply to enable hardware with complex dependencies

If CONFIG_I2C=n:

    WARNING: unmet direct dependencies detected for SND_SOC_AK4642
      Depends on [n]: SOUND [=y] && SND [=y] && SND_SOC [=y] && I2C [=n]
      Selected by [y]:
      - SH_7724_SOLUTION_ENGINE [=y] && CPU_SUBTYPE_SH7724 [=y] && SND_SIMPLE_CARD [=y]

    WARNING: unmet direct dependencies detected for SND_SOC_DA7210
      Depends on [n]: SOUND [=y] && SND [=y] && SND_SOC [=y] && SND_SOC_I2C_AND_SPI [=n]
      Selected by [y]:
      - SH_ECOVEC [=y] && CPU_SUBTYPE_SH7724 [=y] && SND_SIMPLE_CARD [=y]

Fix this by replacing select by imply, instead of adding a dependency on
I2C.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501240836.OvXqmANX-lkp@intel.com/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

arch/sh/boards/Kconfig

@@ -80,8 +80,8 @@ config SH_7724_SOLUTION_ENGINE
 	select SOLUTION_ENGINE
 	depends on CPU_SUBTYPE_SH7724
 	select GPIOLIB
-	select SND_SOC_AK4642 if SND_SIMPLE_CARD
 	select REGULATOR_FIXED_VOLTAGE if REGULATOR
+	imply SND_SOC_AK4642 if SND_SIMPLE_CARD
 	help
 	  Select 7724 SolutionEngine if configuring for a Hitachi SH7724
 	  evaluation board.
@@ -259,8 +259,8 @@ config SH_ECOVEC
 	bool "EcoVec"
 	depends on CPU_SUBTYPE_SH7724
 	select GPIOLIB
-	select SND_SOC_DA7210 if SND_SIMPLE_CARD
 	select REGULATOR_FIXED_VOLTAGE if REGULATOR
+	imply SND_SOC_DA7210 if SND_SIMPLE_CARD
 	help
 	  Renesas "R0P7724LC0011/21RL (EcoVec)" support.