[iOS] disabling D16 and D24S8 texture formats as it appears they are not supported

tested on the full range of iOS devices from iPhone 5s to iPhone 11

src/renderer_gl.cpp

@@ -2086,7 +2086,7 @@ BX_TRACE("%d, %d, %d, %s", _array, _srgb, _mipAutogen, getName(_format) );
 							s_textureFilter[TextureFormat::RGBA32F] = linear32F;
 						}
 
-						if (BX_ENABLED(BX_PLATFORM_IOS) || BX_ENABLED(BX_PLATFORM_EMSCRIPTEN))
+						if (BX_ENABLED(BX_PLATFORM_EMSCRIPTEN))
 						{
 							setTextureFormat(TextureFormat::D16,   GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT, GL_UNSIGNED_SHORT);
 							setTextureFormat(TextureFormat::D24S8, GL_DEPTH_STENCIL,   GL_DEPTH_STENCIL,   GL_UNSIGNED_INT_24_8);