error while compiling latest kernel for ALLWINNER

[Daniel Braniss]

Hi,
this is the error:
…

linking kernel.full
r21au_attach.o: In function `r21au_vap_preattach':
/r+d/vanilla/12/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c:115: undefined reference to `r21au_newstate'
/r+d/vanilla/12/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c:115: undefined reference to `r21au_newstate'
r21au_attach.o: In function `r21a_postattach':
/r+d/vanilla/12/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c:89: undefined reference to `r21au_chan_check'
/r+d/vanilla/12/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c:89: undefined reference to `r21au_chan_check'
/r+d/vanilla/12/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c:96: undefined reference to `r21au_scan_start'
/r+d/vanilla/12/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c:96: undefined reference to `r21au_scan_start'
/r+d/vanilla/12/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c:98: undefined reference to `r21au_scan_end'
/r+d/vanilla/12/sys/dev/rtwn/rtl8821a/usb/r21au_attach.c:98: undefined reference to `r21au_scan_end'
*** Error code 1

Stop.
bmake[2]: stopped in /home/obj/rnd/armv6/orangepi/arm.armv6/r+d/vanilla/12/sys/ALLWINNER
*** Error code 1