rtlwifi: Fix alignment issues

The addresses of Wlan NIC registers are natural alignment, but some
drivers have bugs. These are evident on platforms that need natural
alignment to access registers.  This change contains the following:
 1. Function _rtl8821ae_dbi_read() is used to read one byte from DBI,
    thus it should use rtl_read_byte().
 2. Register 0x4C7 of 8192ee is single byte.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>