clocksource/drivers: Add MStar MSC313e timer support

The MSC313e-compatible SoCs have 3 timer hardware blocks. All of these
are free running 32-bit increasing counters and can generate interrupts.
Based onto a maximum value register, each timer can either count from 0
to max, one time then stop (which generates interrupts) or can count
from 0 to max and then roll. This commit adds basic support for these
timers, the first timer block being used as clocksource/sched_clock
and delay, while the others will be used as clockevents.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Co-developed-by: Daniel Palmer <daniel@0x0f.com>
Signed-off-by: Daniel Palmer <daniel@0x0f.com>
Link: https://lore.kernel.org/r/20211217195727.8955-2-romain.perier@gmail.com


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