clocksource/drivers/owl: Improve owl_timer_init fail messages

Check the return from clocksource_mmio_init, add messages in case of
an error and in case of not having a defined clock property.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200219004810.411190-1-matheus@castello.eng.br

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clocksource/drivers: Unify the names to timer-* format

In order to make some housekeeping in the directory, this patch renames
drivers to the timer-* format in order to unify their names.

There is no functional changes.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>