configfs: Make sure configfs_init() is called before consumers.

configfs_init() needs to be called first to register configfs before anyconsumers try to access it.  Move up configfs in fs/Makefile to make
sure it is initialized early.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>