libgles-omap3: Specify the Window System to be updated in powervr.ini
libgles-omap3: Specify the Window System to be updated in powervr.ini

* SGX driver looks at /etc/powervr.ini for the Window System to be used.
  This patch introduces a variable to specify which Window System should
  be specified in powervr.ini file.
* By having this variable, it's easy to override the default Window System
  through a config file or amendment

Signed-off-by: Anand Balagopalakrishnan <eeda4c1aeb5bc7baa9f2000ba449d4bb376eec3e@ti.com>
Acked-by: Siddharth Heroor <1457302e24e895303aa4b06d008aa2447893910c@ti.com>
Signed-off-by: Denys Dmytriyenko <d29de71aea38aad3a87d486929cb0aad173ae612@ti.com>

rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal