mfd: axp20x: Do not sleep in the power off handler

Since commit 856c288b00 ("ARM: Use do_kernel_power_off()"), the
function axp20x_power_off() now runs inside a RCU read-side critical
section, so it is not allowed to call msleep(). Use mdelay() instead.

Fixes: 856c288b00 ("ARM: Use do_kernel_power_off()")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221105212909.6526-1-samuel@sholland.org

drivers/mfd/axp20x.c

@@ -842,7 +842,7 @@ static void axp20x_power_off(void)
 		     AXP20X_OFF);
 
 	/* Give capacitors etc. time to drain to avoid kernel panic msg. */
-	msleep(500);
+	mdelay(500);
 }
 
 int axp20x_match_device(struct axp20x_dev *axp20x)