Migrate nios2 driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now.

This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED.

Cc: Ley Foon Tan <lftan@altera.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: nios2-dev@lists.rocketboards.org
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NLey Foon Tan <lftan@altera.com>

Display error message if number of timers is less than 2.
Signed-off-by: NLey Foon Tan <lftan@altera.com>

nios2 is the only architecture that does not inline get_cycles
and does not export it.  This breaks crypto as it uses get_cycles
in a number of modules.
Reported-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

The irq member of struct nios2_timer is only written to but
never read, thus it can be removed.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NLey Foon Tan <lftan@altera.com>

Return value of irq_of_parse_and_map() is unsigned int, with 0
indicating failure, so testing for negative result never works.
Signed-off-by: NDmitry Torokhov <dtor@chromium.org>
Reviewed-by: NTobias Klauser <tklauser@distanz.ch>
Acked-by: NLey Foon Tan <lftan@altera.com>

Add time keeping code for nios2.
Signed-off-by: NLey Foon Tan <lftan@altera.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>