edgeos: enable DRM_TTM_HELPER for kernel 6.11+

CONFIG_DRM_TTM_HELPER is required by nvidia driver. However it is not
exposed in the Kconfig so we have to enable it by enabling another
driver that depends on it. DRM_BOCHS is a simple and tiny driver that
depends on CONFIG_DRM_TTM_HELPER.

Reference:
https://forums.developer.nvidia.com/t/bug-550-135-still-broken-with-kernel-6-11-x/313996

BUG=b/422195644
TEST=Built the gmec-amd64-hw image with 6.12 kernel and nvidia driver.
RELEASE_NOTE=None.

Change-Id: Id864617827e0e893cb578d01b7fe9c62cbb7308b
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/105486
Reviewed-by: Kirill Spitsyn <ksp@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
3 files changed