ANDROID: GKI: Fix x86 warning on DMA_VIRTUAL_CHANNELS

Add DMADEVICES=y to the x86 gki_defconfig to fix this warning for x86
builds:

arch/x86/configs/gki_defconfig:361:warning: unexpected data: CONFIG_DMADEVICES=y

WARNING: unmet direct dependencies detected for DMA_VIRTUAL_CHANNELS
  Depends on [n]: DMADEVICES [=n]
  Selected by [y]:
  - GKI_HIDDEN_SND_SOC_CONFIGS [=y]

WARNING: unmet direct dependencies detected for DMA_VIRTUAL_CHANNELS
  Depends on [n]: DMADEVICES [=n]
  Selected by [y]:
  - GKI_HIDDEN_SND_SOC_CONFIGS [=y]

Fixes: dd17237d ("ANDROID: gki: build-in DMA_VIRTUAL_CHANNELS")
Signed-off-by: Todd Kjos <tkjos@google.com>
Change-Id: I6b1613255ca7488748abfbd7e6f626c6e8a000d5