Use sRGB encoded reference values for 8-bit Display P3 tests
Use sRGB encoded reference values for 8-bit Display P3 tests

Per EGL_EXT_gl_colorspace_display_p3 spec, Display P3 assumes
sRGB transfer function. So use the reference values computed
in sRGB space for 8-bit Display P3 tests, instead of linear ones.

Components: AOSP
VK-GL-CTS issue: 1384

Affects:
dEQP-EGL.functional.wide_color.pbuffer_8888_colorspace_p3
dEQP-EGL.functional.wide_color.window_8888_colorspace_p3

Change-Id: I77cf0f84b3189ce4e64f28a83d771b21eccd9214

KhronosGroup/VK-GL-CTS,KhronosGroup/VK-GL-CTS,KhronosGroup/Vulkan-CTS,googlestadia/VK-GL-CTS,googlestadia/VK-GL-CTS,googlestadia/VK-GL-CTS,KhronosGroup/VK-GL-CTS,KhronosGroup/VK-GL-CTS,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/VK-GL-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/Vulkan-CTS,googlestadia/VK-GL-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/Vulkan-CTS,KhronosGroup/VK-GL-CTS,googlestadia/VK-GL-CTS