Fix wrong order of display columns

[caemor]

Currently when cycling through the outer leds of the display in the nonblocking mode the order is broken for the top & bottom row. The current order is 1->4->3->2->5. This PR fixes the issue some of the columns were mixed up and matches with the docs from the microbit. It can be tested by replacing the display_nonblocking example with the slightly modified example here: https://gist.github.com/7b8d71b6b06eb8ab11a5f5f0a13f7a47

[robyoung]

That is really interesting because when I wrote this those two pins were flipped on the V2 device I have (hence the very frustrated comment). I'll retest this evening. It may be that I have a dodgy device.

[cathiele]

I can confirm that with my V2 board this PR fixes the broken ordering of the led-matrix.

[bors[bot]]

Build succeeded:

• build (MSRV)
• build (stable)
• Rustfmt