net/mlx5: Revise gre and nvgre key formats

GRE RFC defines a 32 bit key field. NVGRE RFC splits the 32 bit
key field to 24 bit VSID (gre_key_h) and 8 bit flow entropy (gre_key_l).

Define the two key parsing alternatives in a union, thus enabling both
access methods.

Signed-off-by: Oz Shlomo <ozsh@mellanox.com>
Reviewed-by: Eli Britstein <elibr@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/infiniband/hw/mlx5/main.c

@@ -2680,11 +2680,11 @@ static int parse_flow_attr(struct mlx5_core_dev *mdev, u32 *match_c,
 			 ntohs(ib_spec->gre.val.protocol));
 
 		memcpy(MLX5_ADDR_OF(fte_match_set_misc, misc_params_c,
-				    gre_key_h),
+				    gre_key.nvgre.hi),
 		       &ib_spec->gre.mask.key,
 		       sizeof(ib_spec->gre.mask.key));
 		memcpy(MLX5_ADDR_OF(fte_match_set_misc, misc_params_v,
-				    gre_key_h),
+				    gre_key.nvgre.hi),
 		       &ib_spec->gre.val.key,
 		       sizeof(ib_spec->gre.val.key));
 		break;