clocksource/drivers/timer-of: Don't request the resource by name

clocksource/drivers/timer-of: Don't request the resource by name

When the driver does not specify a name for the resource, don't use
of_io_request_and_map() but of_iomap(). That prevents resource name allocation
conflicts on some platforms which have the same name as the node.

Tested-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1515418139-23276-10-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>