clk: sunxi-ng: fix PRCM CCU ir clk parent

The first parent of ir clk in PRCM CCU is wrongly written as "osc32K"
instead of "osc32k".

Change it to "osc32k".

Fixes: cdb8b80b ("clk: sunxi-ng: add support for PRCM CCUs")

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>