cmd: ufetch: use 3-bit colour ANSI codes

cmd: ufetch: use 3-bit colour ANSI codes

Currently, the 8-bit escapes are being used, which aren't supported by
vidconsole_escape_char. Since the current usage maps directly to the
3-bit equivalents anyway, let's use those instead.

With this change, the fetch output looks as fetching in the vidconsole
as it does over serial!

Signed-off-by: Sam Day <me@samcday.com>
Tested-by: Alexey Minnekhanov <alexeymin@postmarketos.org>
Tested-by: Ferass El Hafidi <funderscore@postmarketos.org>