clk: pxa: Constify static struct clk_ops

clk: pxa: Constify static struct clk_ops

Constify a couple of static struct clk_ops that are not modified. Their
only usage is inside the macros and their address is passed to
clk_register_composite() which takes pointers to const struct clk_ops.
This allows the compiler to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20200922184715.1854-1-rikard.falkeborn@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>