wifi: mwifiex: Support firmware hotfix version in GET_HW_SPEC responses

Support the firmware hotfix version in GET_HW_SPEC responses to avoid an
irritating "Unknown api_id: 5" message on probe.

Based on this commit in NXP's GPLv2-licensed out-of-tree driver:
https://github.com/nxp-imx/mwifiex/commit/27fd8ecca504



Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Sherry Sun <sherry.sun@nxp.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/111c7ee895f12d951e95a2edcd06d87ca26a7d0f.1674827105.git.lukas@wunner.de