iwlwifi: propagate (const) type qualifier

Most of this change is a continuation of commit 403ea939


("iwlwifi: dbg: Mark ucode tlv data as const") propagating the
(const) type qualifier for ucode based tlv data to avoid having
the impression that it is writeable.
The other part of the change preserves the (const) type qualifier
over casts and function calls where it was previously lost.
Both changes are needed to avoid compile time errors on system with
more strict error settings, in this case found with clang on FreeBSD.

Sponsored by:  The FreeBSD Foundation
Signed-off-by: Bjoern A. Zeeb <bz@FreeBSD.ORG>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
[fix double word in commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20220128153014.3230c41312fc.I0032c597984834258d5a79b97052ed83dbe53b80@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>