clk: imx: pll14xx: name variables after usage

In clk_pll1443x_set_rate() 'tmp' is used for the content of different
registers which makes it a bit hard to follow. Use different variables
named after the registers to make it clearer. No functional change
intended.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Link: https://lore.kernel.org/r/20220304125256.2125023-6-s.hauer@pengutronix.de


Signed-off-by: Abel Vesa <abel.vesa@nxp.com>