meson: update default options for libdrm
Libdrm now uses enabled/disabled/auto for the drivers, migrate to these new defaults.
Error message from meson:
wlroots| subprojects/wlroots/subprojects/libdrm/meson.build:21:0: Exception: Value "false" (of type "string") for combo option "Enable support for Intel's KMS API." is not one of the choices. Possible choices are (as string): "enabled", "disabled", "auto".`
Edited by Rouven Czerwinski