Enable the DDR frequency scaling support on i.MX8ULP.
Normally, the freq_index define is as below:
0: boot frequency;
1: low frequency(PLL bypassed);
2. high frequency(PLL ON).
Currently, DDR DFS only do frequency switching between
Low freq and high freq.
Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Ye Li <ye.li@nxp.com>
Change-Id: I3acd8bdf75e2dd6dff645b9f597dcfc0a756c428
