spl: binman: Declare extern symbols for VPL as well

The binman extern symbol declarations in spl.h are missing the VPL
symbols recently added to spl.c, add them like the others.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
diff --git a/include/spl.h b/include/spl.h
index 83ac583..1778e0f 100644
--- a/include/spl.h
+++ b/include/spl.h
@@ -288,6 +288,8 @@
 binman_sym_extern(ulong, u_boot_any, size);
 binman_sym_extern(ulong, u_boot_spl, image_pos);
 binman_sym_extern(ulong, u_boot_spl, size);
+binman_sym_extern(ulong, u_boot_vpl, image_pos);
+binman_sym_extern(ulong, u_boot_vpl, size);
 
 /**
  * spl_get_image_pos() - get the image position of the next phase