common/mlx5: move some getter functions from net driver

common/mlx5: move some getter functions from net driver

Getter functions such as: 'mlx5_os_get_ctx_device_name',
'mlx5_os_get_ctx_device_path', 'mlx5_os_get_dev_device_name',
'mlx5_os_get_umem_id' are implemented under net directory. To enable
additional devices (e.g. regex, vdpa) to access these getter functions
they are moved under common directory.

As part of this commit string sizes DEV_SYSFS_NAME_MAX and
DEV_SYSFS_PATH_MAX are increased by 1 to make sure that the destination
string size in strncpy() function is bigger than the source string size.
This update will avoid GCC version 8 error -Werror=stringop-truncation.

Signed-off-by: Ophir Munk <ophirmu@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>