ice: introduce context struct for info report

ice: introduce context struct for info report

The ice driver uses an array of structures which link an info name with
a function that formats the associated version data into a string.

All existing format functions simply format already captured static data
from the driver hw structure. Future changes will introduce format
functions for reporting the versions of flash sections stored but not
yet applied. This type of version data is not stored as a member of the
hw structure. This is because (a) it might not yet exist in the case
there is no pending flash update, and (b) even if it does, it might
change such as if an update is canceled or replaced by a new update
before finalizing.

We could simply have each format function gather its own data upon being
called. However, in some cases the raw binary version data is
a combination of multiple different reported fields. Additionally, the
current interface doesn't have a way for the function to indicate that
the version doesn't exist.

Refactor this function interface to take a new ice_info_ctx structure
instead of the buffer pointer and length. This context structure allows
for future extensions to pre-gather version data that is stored within
the context struct instead of the hw struct.

Allocate this context structure initially at the start of
ice_devlink_info_get. We use dynamic allocation instead of a local stack
variable in order to avoid using too much kernel stack once we extend it
with additional data structures.

Modify the main loop that drives the info reporting so that the version
buffer string is always cleared between each format. Explicitly check
that the format function actually filled in a version string of non-zero
length. If the string is not provided, simply skip this version without
reporting an error. This allows for introducing format functions of
versions which may or may not be present, such as the version of
a pending update that has not yet been activated.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>