egl_helper: use eglGetPlatformDisplay() for KMS/GDM when possible
egl_helper: use eglGetPlatformDisplay() for KMS/GDM when possible

When using the KMS/GBM backend, and when EGL 1.5 is available,
eglGetPlatformDisplay() will be used instead of eglGetDisplay().

This was needed to work around an EGL driver initialization crash on
Vivante gpu-viv6 on i.MX8 platforms.

Signed-off-by: Julien Olivain <7fdfe229fce69a4d7f38653f3755ccbae5703f88@cotds.org>

jolivain/glslsandbox-player,jolivain/glslsandbox-player,jolivain/glslsandbox-player,jolivain/glslsandbox-player