This function is called on each redraw of UI. Due to using external
command 'date' to create timestamp, trace logging noticeably slows down
UI draw time in the middle.
Another possible fixes:
- disable timestamp in trace logging
- generate RAM info only once before UI shows as it is unlikely RAM will
change while DTS is running
Signed-off-by: Michał Iwanicki <michal.iwanicki@3mdeb.com>