driver: ddr: Refine the ddr init driver on imx8m

Refine the ddr init driver to make it more reusable for different
DDR type(LPDDR4, DDR4 & DDR3L). So we can reduce some redundant
code.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>

drivers/ddr/imx/imx8m/ddrphy_utils.c

@@ -122,6 +122,10 @@ void ddrphy_init_set_dfi_clk(unsigned int drate)
 		dram_pll_init(MHZ(400));
 		dram_disable_bypass();
 		break;
+	case 1066:
+		dram_pll_init(MHZ(266));
+		dram_disable_bypass();
+		break;
 	case 667:
 		dram_pll_init(MHZ(167));
 		dram_disable_bypass();