Fix disabling display power.

display/firmware/src/display.rs

         let epd = EPD4in2::new(spi, pins.cs, pins.busy, pins.dc, pins.rst, &mut time).unwrap(); // TODO: Error handling?
 
         // Disable power again.
-        pins.pwr.set_low().ok();
+        pins.pwr.set_high().ok();
 
         Display { pwr: pins.pwr, epd }
     }