rtlwifi: rtl8821ae: Convert driver to use common hardware info routine

The driver for RTL8821AE chips is converted to use the common routine
for getting the hardware information.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>