Unify default dpi between eglfs and linuxfb

Task-number: QTBUG-37251
Change-Id: I4ab8e645441f6ad3a122304e1ead050b48fafbac
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

src/plugins/platforms/linuxfb/qlinuxfbscreen.cpp

@@ -148,7 +148,7 @@ static QSizeF determinePhysicalSize(const fb_var_screeninfo &vinfo, const QSize
             mmWidth = vinfo.width;
             mmHeight = vinfo.height;
         } else {
-            const int dpi = 72;
+            const int dpi = 100;
             mmWidth = qRound(res.width() * 25.4 / dpi);
             mmHeight = qRound(res.height() * 25.4 / dpi);
         }