non-OF initialisation has never been used with any cache controller
which isn't an ARM cache controller, so we can safely get rid of the
old (and buggy) l2x0_*-based operations structure.

This is also the last reference to:
- l2x0_clean_line()
- l2x0_inv_line()
- l2x0_flush_line()
- l2x0_flush_all()
- l2x0_clean_all()
- l2x0_inv_all()
- l2x0_inv_range()
- l2x0_clean_range()
- l2x0_flush_range()
- l2x0_enable()
- l2x0_resume()
so kill those functions too.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>