Use a single mechanism to show driver version.
Reduces text a tiny bit too.

Remove uses of static int printed_version
Add and use ata_print_version(const struct device *, const char *ver)
and ata_print_version_once.

$ size drivers/ata/built-in.*
   text	   data	    bss	    dec	    hex	filename
 544969	  73893	 116584	 735446	  b38d6	drivers/ata/built-in.allyesconfig.ata.o
 543870	  73893	 116592	 734355	  b34ad	drivers/ata/built-in.allyesconfig.print_once.o
 141328	  14689	   4220	 160237	  271ed	drivers/ata/built-in.defconfig.ata.o
 141212	  14689	   4220	 160121	  27179	drivers/ata/built-in.defconfig.print_once.o

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>