frameworks/base: Disable H/w GL rendering based on property

"ro.nohardwaregfx" can be set to true to have software
rendering.The property could be set for each board by adding
the 2 lines to device.mk file.

PRODUCT_PROPERTY_OVERRIDES += \
            ro.nohardwaregfx=true

Based on ICS patch from Vishal Bhoj <Vishal.Bhoj@linaro.org>

Change-Id: I547258ee021034102fe8d8e7cc0cdfa8a63df298
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>