doc: doxygen: exclude nrf_wifi

This one appears in the top level of doxygen and should not be exposed
as a Zephyr API.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

Author: nashif

doc/zephyr.doxyfile.in

@@ -1039,7 +1039,8 @@ RECURSIVE              = YES
 # run.
 
 EXCLUDE                = @ZEPHYR_BASE@/include/zephyr/portability/cmsis_os.h \
-                         @ZEPHYR_BASE@/include/zephyr/portability/cmsis_os2.h
+                         @ZEPHYR_BASE@/include/zephyr/portability/cmsis_os2.h \
+                         @ZEPHYR_BASE@/include/zephyr/drivers/wifi/nrf_wifi
 
 # The EXCLUDE_SYMLINKS tag can be used to select whether or not files or
 # directories that are symbolic links (a Unix file system feature) are excluded