MIPS: ath79: Switch to the clkdev framework

MIPS: ath79: Switch to the clkdev framework

The ath79 code uses static clock devices and
provides its own clk_{get,put} implementations.

Change the code to use dynamically allocated
clock devices and register the clocks within
the clkdev framework.

Additionally, remove the local clk_{get,put}
implementation. The clkdev framework has a
common implementation of those.

Also move the call of ath79_clock_init() from
plat_mem_init() to plat_time_init(). Otherwise
it would not be possible to use memory allocation
functions from ath79clock_init() becasuse the
memory subsystem is not yet initialized when
plat_mem_init() runs.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5780/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>