mei: hw: don't use one element arrays

mei: hw: don't use one element arrays

Replace the single element arrays with a simple value type u8 reserved,
even thought is is not used for dynamically sized trailing elements
it confuses the effort of replacing one-element arrays with
flexible arrays for that purpose.

Link: https://github.com/KSPP/linux/issues/79
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20200723145927.882743-7-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>