trace: Use explicit alignment requirements to avoid misalignment

trace: Use explicit alignment requirements to avoid misalignment

64-bit builds with CONFIG_WPA_TRACE=y resulted in the wpabuf pointers
getting misaligned (only 32-bit aligned) and that would result in reads
and writes of unaligned size_t values. Avoid this by indicating explicit
alignment requirement for wpabuf_trace to 8 octets (i.e., there will be
extra four octets of padding in case of 64-bit builds).

Similarly, struct os_alloc_trace resulted in some potential misalignment
cases, e.g., when CONFIG_ACS=y uses a 'long double' variable within
struct hostapd_channel_data. Avoid misalignment issues with explicit
alignment indication.

Signed-off-by: Jouni Malinen <j@w1.fi>