isl923x: Don't initialize ICL on sysjump.

The ISL923x init function would initialize the charger's input current
to the board's defined default.  For some boards like meowth and
zoombini, the default input current was set quite low, 128mA.  When
sysjumping, all HOOK_INITs are called again and therefore the input
current limit would be reset even thought it would have been set
correctly prior to jumping.  Setting the current limit so low, without a
battery, would cause a power failure and the PMIC would drop its power
OK signal and go into emergency shutdown.

This commit simply adds a check to whether the EC jumped to this image.
If it has, the charger input current limit is left unchanged.  It will
be updated to the correct value by charge manager later on after
determine the attached charge supplier.

BUG=b:72129338
BRANCH=None
TEST=Flash meowth; Boot to S0 without a battery; Verify that PMIC_DPWROK
remains high.
TEST=Repeat above test for zoombini.

Change-Id: I7e5bbbbf3ec604c876cc4fa0163f8bb7feff4cc9
Signed-off-by: Aseda Aboagye <aaboagye@google.com>
Reviewed-on: https://chromium-review.googlesource.com/896960
Commit-Ready: Aseda Aboagye <aaboagye@chromium.org>
Tested-by: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Caveh Jalali <caveh@google.com>

driver/charger/isl923x.c

@@ -14,6 +14,7 @@
 #include "hooks.h"
 #include "i2c.h"
 #include "isl923x.h"
+#include "system.h"
 #include "task.h"
 #include "timer.h"
 #include "util.h"
@@ -365,6 +366,13 @@ static void isl923x_init(void)
 	if (raw_write16(ISL9238_REG_CONTROL3, reg))
 		goto init_fail;
 
+	/*
+	 * No need to proceed with the rest of init if we sysjump'd to this
+	 * image as the input current limit has already been set.
+	 */
+	if (system_jumped_to_this_image())
+		return;
+
 	/*
 	 * Initialize the input current limit to the board's default.
 	 */