net/mlx5e: Use runtime page_shift for striding RQ

This commit allows striding RQ to determine MTT page size at runtime,
instead of sticking to the compile-time PAGE_SIZE. This functionality
will be used by a following commit that adjusts the MTT page size to the
XSK frame size.

Stick with PAGE_SIZE for XSK on legacy RQ, as frag_stride is not used in
data path, it only helps calculate how pages are partitioned into
fragments, and PAGE_SIZE will ensure each fragment starts at the
beginning of a new allocation unit (XSK frame).

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/mlx5/qp.h

@@ -162,6 +162,8 @@ enum {
 	MLX5_SEND_WQE_MAX_WQEBBS	= 16,
 };
 
+#define MLX5_SEND_WQE_MAX_SIZE (MLX5_SEND_WQE_MAX_WQEBBS * MLX5_SEND_WQE_BB)
+
 enum {
 	MLX5_WQE_FMR_PERM_LOCAL_READ	= 1 << 27,
 	MLX5_WQE_FMR_PERM_LOCAL_WRITE	= 1 << 28,