device property: Add missed header in fwnode.h

device property: Add missed header in fwnode.h

When adding some stuff to the header file we must not rely on
implicit dependencies that are happen by luck or bugs in other
headers. Hence fwnode.h needs to use bits.h directly.

Fixes: c2c724c868c4 ("driver core: Add fw_devlink_parse_fwtree()")
Cc: Saravana Kannan <saravanak@google.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211013143707.80222-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>