net/mlx5: Increase hairpin buffer size

The max packet size a hairpin queue is able to handle
is determined by the total hairpin buffer size divided
by 4.

Currently the buffer size is set to 32KB which makes
the max packet size to be 8KB and doesn't support
jumbo frames of size 9KB.

This change increases the buffer size to 64KB to increase
the max frame size and support 9KB frames.

Signed-off-by: Ariel Levkovich <lariel@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>