Framebuffer console: Add spleen font (12x24)

Use this larger font when the screen resolution is large (more than
1920x1080 in both directions). The usual font is too small and not easy
to read on such high resolution displays.

Change-Id: I14a40ecf6917d0c6c64ab5a8abe1affcb3839a74
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3818
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>
Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>