QDbus: Fix (!a == b) comparison

! binds to a, and that is wrong here.

(cherry picked from qtbase/4b7cd57719a637189696d673b014ae785df669bf)

Change-Id: I75542a0c27f39fb6e684dedd9925a1f3748d4919
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Fix compilation using MinGW 64 due to missing __cpuid

Compile fails on Windows 64 using MinGW with the error message:
'__cpuid' was not declared in this scope.

fix by moving the Q_CC_GNU block above the WIN64 block
as suggested by Thiago in the QTBUG-34022 comments.

Task-number: QTBUG-34022
Change-Id: Iced4ac0b64f8ba986e49543ff3793ae8c0c33d14
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>