Input: drv260x - sleep between polling GO bit

When doing the initial startup there's no need to poll without any
delay and spam the I2C bus.

Let's sleep 15ms between each attempt, which is the same time as used
in the vendor driver.

Fixes: 7132fe4f56 ("Input: drv260x - add TI drv260x haptics driver")
Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Link: https://lore.kernel.org/r/20230430-drv260x-improvements-v1-2-1fb28b4cc698@z3ntu.xyz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/misc/drv260x.c

@@ -435,6 +435,7 @@ static int drv260x_init(struct drv260x_data *haptics)
 	}
 
 	do {
+		usleep_range(15000, 15500);
 		error = regmap_read(haptics->regmap, DRV260X_GO, &cal_buf);
 		if (error) {
 			dev_err(&haptics->client->dev,