w1: ds250x: Fix build error without CRC16

If CRC16 is not set, building will fails:

drivers/w1/slaves/w1_ds250x.o: In function `w1_ds2505_read_page':
w1_ds250x.c:(.text+0x82f): undefined reference to `crc16'
w1_ds250x.c:(.text+0x90a): undefined reference to `crc16'
w1_ds250x.c:(.text+0x91a): undefined reference to `crc16'
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 25ec8710 ("w1: add DS2501, DS2502, DS2505 EPROM device driver")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20190920060318.35020-1-yuehaibing@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/w1/slaves/Kconfig

@@ -103,6 +103,7 @@ config W1_SLAVE_DS2438
 
 config W1_SLAVE_DS250X
 	tristate "512b/1kb/16kb EPROM family support"
+	select CRC16
 	help
 	  Say Y here if you want to use a 1-wire
 	  512b/1kb/16kb EPROM family device (DS250x).