acpi: Put the version numbers in a central place

At present two acpi files are built every time since they use a version
number from version.h

This is not necessary. Make use of the same technique as for the version
string, so that they are build only when they change.

Signed-off-by: Simon Glass <sjg@chromium.org>

cmd/version.c

@@ -19,6 +19,8 @@
 	U_BOOT_TIME " " U_BOOT_TZ ")" CONFIG_IDENT_STRING
 
 const char version_string[] = U_BOOT_VERSION_STRING;
+const unsigned short version_num = U_BOOT_VERSION_NUM;
+const unsigned char version_num_patch = U_BOOT_VERSION_NUM_PATCH;
 
 static int do_version(struct cmd_tbl *cmdtp, int flag, int argc,
 		      char *const argv[])