ram: rk3399: Add lpddr4 rank mask for ca training

Add rank_mask based on the rank number for lpddr4.

This would keep the ca data training loop based on the
desired rank mask value instead of looping for all values.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: YouMin Chen <cym@rock-chips.com>
Reviewed-by: Kever Yang <Kever.yang@rock-chips.com>
diff --git a/drivers/ram/rockchip/sdram_rk3399.c b/drivers/ram/rockchip/sdram_rk3399.c
index cca809a..b7cad92 100644
--- a/drivers/ram/rockchip/sdram_rk3399.c
+++ b/drivers/ram/rockchip/sdram_rk3399.c
@@ -687,7 +687,10 @@
 	/* clear interrupt,PI_175 PI_INT_ACK:WR:0:17 */
 	writel(0x00003f7c, (&denali_pi[175]));
 
-	rank_mask = (rank == 1) ? 0x1 : 0x3;
+	if (params->base.dramtype == LPDDR4)
+		rank_mask = (rank == 1) ? 0x5 : 0xf;
+	else
+		rank_mask = (rank == 1) ? 0x1 : 0x3;
 
 	for (i = 0; i < 4; i++) {
 		if (!(rank_mask & (1 << i)))