QOpenGLTextureHelper: de-inline the DSA / DSA emulator wrappers

There's no advantage at keeping them inline because we never call them
directly: we take pointers to them. This can actually cause
multiple copies of the function to be emitted, then the linker may or
may not decide to discard N-1 copies. Just avoid this route
and deinline them.

Change-Id: I5adc704b50ec7f26498846fcbb86cb5b5d016b4b
Reviewed-by: James Turner <james.turner@kdab.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Remove unused private member (fixes compilation with Clang 3.4)

qkmsscreen.h:114:18: error: private field 'm_refreshTime' is not used

Change-Id: Id9c802c5c3ae2ffdf61238f083bfe875e7b613a8
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>