feat(imx8mq): correct the slot ack setting for STOP mode

A53 core's power up ack need to be used when system resume
from DSM mode.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: I47fb33c0582ae5f483ffaa887f95e27bd47875f7
diff --git a/plat/imx/imx8m/imx8mq/gpc.c b/plat/imx/imx8m/imx8mq/gpc.c
index c036e13..0a029d6 100644
--- a/plat/imx/imx8m/imx8mq/gpc.c
+++ b/plat/imx/imx8m/imx8mq/gpc.c
@@ -261,7 +261,7 @@
 		mmio_setbits_32(IMX_GPC_BASE + SLTx_CFG(2), SLT_COREx_PUP(last_core));
 		/* ACK setting: PLAT ACK for PDN, CORE ACK for PUP */
 		mmio_clrsetbits_32(IMX_GPC_BASE + PGC_ACK_SEL_A53, 0xFFFFFFFF,
-			A53_PLAT_PDN_ACK | A53_PLAT_PUP_ACK);
+			A53_PLAT_PDN_ACK | SLT_COREx_PUP_ACK(last_core));
 	} else {
 		mmio_clrbits_32(IMX_GPC_BASE + SLTx_CFG(0), 0xFFFFFFFF);
 		mmio_clrbits_32(IMX_GPC_BASE + SLTx_CFG(1), 0xFFFFFFFF);