Merge tag libdrm-2.4.75 into aosp/master

Below is a brief summary of patches pulled in:
0da99b8a (m/master, aosp/master) Move to vendor partition
d4b83443 (tag: libdrm-2.4.75) Bump version for 2.4.75 release
dae413e4 (tag: libdrm-2.4.74) Bump version for release
317bdff1 (tag: libdrm-2.4.73) Bump version for release
8cf43127 (tag: libdrm-2.4.72) Bump version for release
a44c9c31 (tag: libdrm-2.4.71) Bump version for release
20208455 (tag: android-o-preview-1, tag: android-n-mr2-preview-2, tag:
android-n-mr2-preview-1, aosp/sdk-release, aosp/o-preview) add a flag
control that private libdrm can be chosen

Bug: 35871718
Test: aosp_arm-eng compiles
Change-Id: I81985fd41d5c0d8a732705dc2a4bee8eb5d459bb