qtbase.inc: set virtual/mesa and virtual/egl as dependency in PACKAGECONFIG[kms]

* there is no kms around
* mesa is the default implementation for (lib)gbm
* in configure we find:
  | if [ "$CFG_KMS" = "yes" ]; then
  |     if [ "$CFG_EGL" = "no" ]; then
  |         echo "The KMS plugin requires EGL support and cannot be built"
  |         exit 101
  |     fi
  | fi

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>