Revert to the pre highdpi-patch behaviour.
Before, both physical and logical DPI would be based
on the dpmx/dpmy variables, which could be changed
with setDotsPerMeter(). The highdpi patch introduced
separate ldpmx/ldpmy variables, which were not
changed by setDotsPerMeter().
This broke when loading images: setDotsPerMeter
would be called but the logical dpi would not change.
Remove ldpmx/ldpmy. Keep scaling the physical dpi
by the devicePixelRatio, which will be set to 1 by
default.
Task-number: QTBUG-29187
Change-Id: I0d6f5f3b8efae5fb1adc0a50b22a5da78324a282
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>