hwmon: (sht15) Select CONFIG_BITREVERSE

If CONFIG_BITREVERSE is not built-in, the sht15 driver fails to link:

drivers/built-in.o: In function `sht15_crc8':
drivers/hwmon/sht15.c:195: undefined reference to `byte_rev_table'

This adds a Kconfig 'select' statement, like all other users of
bitrev.h have it.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 33836ee9 ("hwmon:change sht15_reverse()")
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>

drivers/hwmon/Kconfig

@@ -1217,6 +1217,7 @@ config SENSORS_PWM_FAN
 config SENSORS_SHT15
 	tristate "Sensiron humidity and temperature sensors. SHT15 and compat."
 	depends on GPIOLIB || COMPILE_TEST
+	select BITREVERSE
 	help
 	  If you say yes here you get support for the Sensiron SHT10, SHT11,
 	  SHT15, SHT71, SHT75 humidity and temperature sensors.