clk: imx: Update the pfdv2 for 8ulp specific support

On i.MX8ULP, the 'CLK_SET_RATE_PARENT' flag should NOT be
set and according to the laest RM, the PFD divider value range
seems will be changed in the future, so update the pfdv2 to
include the specific support for i.MX8ULP.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Link: https://lore.kernel.org/r/20210914065208.3582128-8-ping.bai@nxp.com
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>