ad_ip_alt.tcl: ad_ip_addfile: Add support for header files

Handle files with a .h suffix and add them as VERILOG_INCLUDE to the file
list.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

library/scripts/adi_ip_alt.tcl

@@ -150,6 +150,10 @@ proc ad_ip_addfile {pname pfile} {
     add_fileset_file $pmodule VERILOG PATH $pfile
     return
   }
+  if {$ptype eq ".h"} {
+    add_fileset_file $pmodule VERILOG_INCLUDE PATH $pfile
+    return
+  }
   if {$ptype eq ".sdc"} {
     add_fileset_file $pmodule SDC PATH $pfile
     return