modem: hl7800: change sleep mode

Sleep mode 0 (driven by DTR) is only recommended for use
as a legacy option.
Sleep mode 1 is recommend by Sierra Wireless.

Signed-off-by: Ryan Erickson <[email protected]>

Author: rerickson1

drivers/modem/hl7800.c

@@ -4767,7 +4767,7 @@ static int modem_reset_and_configure(void)
 	SEND_AT_CMD_EXPECT_OK("AT+KHWIOCFG=3,1,6");
 
 	/* Turn on sleep mode */
-	SEND_AT_CMD_EXPECT_OK("AT+KSLEEP=0,2,10");
+	SEND_AT_CMD_EXPECT_OK("AT+KSLEEP=1,2,10");
 
 #if CONFIG_MODEM_HL7800_PSM
 	/* Turn off eDRX */