cris: remove deprecated IRQF_DISABLED

This patch proposes to remove the IRQF_DISABLED flag from CRIS
architecture code. It's a NOOP since 2.6.35 and it will be removed
one day.

Comments mentioning IRQF_DISABLED are also updated, knowing
that all interrupts are now "fast interrupts", their handlers
running with interrupts disabled.

Don't hesitate to let me know if you have other ways of
rephrasing the comments!

This is an update for 3.11 of a patch already sent for 3.10

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Jesper Nilsson <jespern@axis.com>