wifi: ath10k: improve structure padding

Including an aligned structure inside of a packed one is ambiguous
and can lead to misaligned data, as pointed out by this clang warning:

drivers/net/wireless/ath/ath10k/htt.h:715:34: error: field prefix within 'struct htt_rx_indication' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]
        struct htt_rx_indication_prefix prefix;
                                        ^
drivers/net/wireless/ath/ath10k/htt.h:736:34: error: field prefix within 'struct htt_rx_indication_hl' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication_hl' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]
        struct htt_rx_indication_prefix prefix;
                                        ^
drivers/net/wireless/ath/ath10k/htt.h:1564:2: error: field  within 'struct htt_tx_fetch_ind' is less aligned than 'union htt_tx_fetch_ind::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1564:2)' and is usually due to 'struct htt_tx_fetch_ind' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]
        union {
        ^
drivers/net/wireless/ath/ath10k/htt.h:1702:2: error: field  within 'struct htt_resp' is less aligned than 'union htt_resp::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1702:2)' and is usually due to 'struct htt_resp' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access]

These structures appear to actually need the packing since they
are embedded at misaligned offsets. Add even more such annotations
here to enforce bytewise access throughout the driver.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230616090439.2484857-1-arnd@kernel.org