linux-imx

MLK-23131-2 soc: imx: busfreq-imx8mq: Correct dram pll clock for rate update

When DRAM PLL clock is changed in TF-A, the DRAM PLL clock rate needs
to be updated, previous implementation uses dram_pll_clk which is
clock gate and it will NOT trigger clock rate update, need to use PLL
type clock which has CLK_GET_RATE_NOCACHE flag set and will trigger
clock rate recalculation. Otherwise, when system enters low bus mode,
checking clock rate via "cat /sys/kernel/debug/clk/dram_core_clk/clk_rate"
will NOT return the latest dram core clk rate.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Robin Gong <yibin.gong@nxp.com>