linux-sunxi: disable glamor build if Mali is used
linux-sunxi: disable glamor build if Mali is used

Unless somebody writes libgbm replacement for binary Mali driver
(sort of converter for gbm-UMB) there is no glamor for us.

Closes #227

linux-sunxi/meta-sunxi,twoerner/meta-sunxi,net147/meta-sunxi,net147/meta-sunxi,linux-sunxi/meta-sunxi,linux-sunxi/meta-sunxi,twoerner/meta-sunxi