clocksource: ep93xx: Add driver for Cirrus Logic EP93xx

Rewrite EP93xx timer driver located in arch/arm/mach-ep93xx/timer-ep93xx.c
trying to do everything the device tree way:

- Make every IO-access relative to a base address and dynamic
  so we can do a dynamic ioremap and get going.
- Find register range and interrupt from the device tree.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20230915-ep93xx-v4-12-a1d779dcec10@maquefel.me