staging: xillybus: Added "select CRC32" for XILLYBUS in Kconfig

Reason: xillybus_core.c uses crc32_le()

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>