config: replace deprecated AM_CONFIG_HEADER with AC_CONFIG_HEADERS
config: replace deprecated AM_CONFIG_HEADER with AC_CONFIG_HEADERS

Signed-off-by: Gaetan Nadon <8a8cc541338200f67d4d0bcb65c78b6166649462@videotron.ca>

freedesktop-unofficial-mirror/xorg__driver__xf86-video-suncg14,freedesktop-unofficial-mirror/xorg__driver__xf86-video-suncg14