video: console: Parse UTF-8 character sequences

video: console: Parse UTF-8 character sequences

efi_console / UEFI applications (grub2, sd-boot, ...) pass UTF-8
character sequences to vidconsole which results in wrong glyphs for code
points outside of ASCII. The truetype console expects Unicode code
points and bitmap font based consoles expect code page 437 code points.
To support both convert UTF-8 to UTF-32 and pass Unicode code points in
vidconsole_ops.putc_xy(). These can be used directly in console_truetype
and after conversion to code page 437 in console_{normal,rotate}.

This fixes rendering of international, symbol and box drawing characters
used by UEFI applications.

Signed-off-by: Janne Grunau <j@jannau.net>