wifi: rtw88: add __packed attribute to efuse layout struct

The layout struct of efuse should not do address alignment by compiler.
Otherwise it leads unexpected layout and size for certain arch suc as arm.
In x86-64, the results are identical before and after this patch.

Also adjust bit-field to prevent over adjacent byte to avoid warning:
  rtw88/rtw8822b.h:66:1: note: offset of packed bit-field `res2` has changed in GCC 4.4
   66 | } __packed;
      | ^

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202412120131.qk0x6OhE-lkp@intel.com/


Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20241212054203.135046-1-pkshih@realtek.com