fb: Remove unused cursors ioctls

The cursors related ioctls were added in 1994 with the 4.4 Lite import
but were never implemented in either sc(4), fb(4) or vt(4).
Remove it.

Reviewed by: emaste, tsoome
MFC after: 2 weeks
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D33217

(cherry picked from commit b9d3b253e2f7c4910bbd3844158a2a80f9a7ff4f)

arm/freescale: remove FBIOSCURSOR

Unbreaks building EFIKA_MX

Fixes: b9d3b253e2f7c491 ("fb: Remove unused cursors ioctls")
Sponsored by: Rubicon Communications, LLC ("Netgate")

(cherry picked from commit 793c74e415abf3c7e44c2df1472fdffde620f8e4)