Adding MinGW 4.9.1 labels for QNX build target dirs.

MinGW 4.9.1 label added for QNX targets, and also target directory name changed.

Change-Id: Ia9f524f56517fa128d055477e65ff3c53b4b29f2
Reviewed-by: Iikka Eklund <iikka.eklund@theqtcompany.com>