wifi: cw1200: restore endian swapping

The code here looks well thought-out, so it seems likely
that the byte-swaps are actually needed, due to SPI bus
and device behaviour. Restore the byte-swapping, in a way
that doesn't result in sparse warnings.

Fixes: 7ceade65

 ("wifi: cw1200: fix __le16 sparse warnings")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240228121156.62f820aa6dfb.Ia63314e4d0ed1ee76f100846d68f0722abf6b793@changeid