Fix document for fuzzy match and GRE
Fixes: a3a2e2c8f7de ("ethdev: add fuzzy match in flow API")
Fixes: 7cd048321d1d ("ethdev: add MPLS and GRE flow API items")
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>