rockchip: rk3399: Move DQS drive strength setting to M0

This moves the setting of the DQS drive strength to the M0 to minimize
the impact on DDR transactions. We need to have the DQS drive strength
changed for data training, which is triggered by the M0, but it also
needs to be changed back when data training is finished.
Signed-off-by: Derek Basehore <dbasehore@chromium.org>

plat/rockchip/rk3399/drivers/dram/dfs.c

@@ -1575,7 +1575,6 @@ static void gen_rk3399_phy_params(struct timing_related_config *timing_config,
 				break;
 		}
 		mmio_clrsetbits_32(PHY_REG(i, 947), 0x7 << 8, tmp << 8);
-		mmio_setbits_32(PHY_REG(i, 927), (1 << 22));
 
 		if (timing_config->dram_type == DDR3) {
 			mem_delay_ps = 0;

plat/rockchip/rk3399/drivers/m0/src/dram.c

@@ -81,6 +81,8 @@ static void ddr_set_pll(void)
 
 void handle_dram(void)
 {
+	mmio_setbits_32(PHY_REG(0, 927), (1 << 22));
+	mmio_setbits_32(PHY_REG(1, 927), (1 << 22));
 	idle_port();
 
 	mmio_write_32(CIC_BASE + CIC_CTRL0,
@@ -96,4 +98,6 @@ void handle_dram(void)
 		continue;
 
 	deidle_port();
+	mmio_clrbits_32(PHY_REG(0, 927), (1 << 22));
+	mmio_clrbits_32(PHY_REG(1, 927), (1 << 22));
 }