fbcon: Streamline setting rotated/unrotated bitops

fbcon: Streamline setting rotated/unrotated bitops

Support for console rotation is somewhat bolted onto the helper
fbcon_set_bitops() for unrotated displays.

Update fbcon_set_bitops() with a switch statement that picks the
correct settings helper for the current rotation. For unrotated
consoles, set the bitops for in the new helper fbcon_set_bitops_ur().
Rename the other, existing helpers to match the common naming
scheme.

The old helper fbcon_set_rotate() is no longer used.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://lore.kernel.org/r/20250909124616.143365-6-tzimmermann@suse.de