clk: qoriq: use macros to generate pll_mask

Use macros to generate pll_mask to make code
more readable.

Signed-off-by: Wasim Khan <wasim.khan@nxp.com>
Link: https://lore.kernel.org/r/20210125142513.3919014-1-wasim.khan@oss.nxp.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>