ALSA: vx: fix kernel-doc warning

make W=1 warning:

sound/drivers/vx/vx_core.c:410: warning: expecting prototype for
snd_vx_boot_xilinx(). Prototype was for snd_vx_load_boot_image()
instead

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210302215430.87309-2-pierre-louis.bossart@linux.intel.com


Signed-off-by: Takashi Iwai <tiwai@suse.de>