clk: get clock pointer before proceeding

clk: get clock pointer before proceeding

clk_get_by_indexed_prop() retrieves a clock with dev member being set
with the pointer to the udevice for the clock controller driver. But
in case of CCF each clock driver has set in dev member the reference
to its parent (the root of the clock tree is a fixed clock, every
node in clock tree is a clock registered with clk_register()). In this
case the subsequent operations like dev_get_clk_ptr() on clocks
retrieved by clk_get_by_indexed_prop() will fail. For this, get the
pointer to the proper clock registered (with clk_register()) using
clk_get_by_id() before proceeding.

Fixes: 1d7993d1d0ef ("clk: Port Linux common clock framework [CCF] for imx6q to U-boot (tag: v5.1.12)")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>