platform: arm64: thinkpad-t14s-ec: sleep after EC access

The ACPI ECRD and ECWR functions have a 10ms sleep at the end. It turns
out, that this is sometimes needed to avoid I2C transmission failures,
especially for functions doing regmap_update_bits (and thus read + write
shortly after each other). This fixes problems like the following
appearing in the kernel log:

leds platform::micmute: Setting an LED's brightness failed (-6)
leds platform::kbd_backlight: Setting an LED's brightness failed (-6)

The ACPI QEVT function used to read the interrupt status register also
has a 10ms sleep at the end. Without that there are problems with
reading multiple events following directly after each other resulting
in the following error message being logged:

thinkpad-t14s-ec 4-0028: Failed to read event

Fixes: 60b7ab6 ("platform: arm64: thinkpad-t14s-ec: new driver")
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Link: https://patch.msgid.link/20251119-thinkpad-t14s-ec-improvements-v2-2-441219857c02@kernel.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: sre

drivers/platform/arm64/lenovo-thinkpad-t14s.c

@@ -120,6 +120,7 @@ static int t14s_ec_write(void *context, unsigned int reg,
 	if (ret < 0)
 		return ret;
 
+	fsleep(10000);
 	return 0;
 }
 
@@ -157,6 +158,7 @@ static int t14s_ec_read(void *context, unsigned int reg,
 
 out:
 	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	fsleep(10000);
 	return ret;
 }
 
@@ -191,6 +193,8 @@ static int t14s_ec_read_evt(struct t14s_ec *ec, u8 *val)
 	if (ret < 0)
 		goto out;
 
+	fsleep(10000);
+
 	ret = 0;
 
 out: