target/xtensa/import_core.sh: fix #include <xtensa-isa.h>

Change #include <xtensa-isa.h> to #include "xtensa-isa.h" in imported
files to make references to local files consistent.
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

target/xtensa/import_core.sh

@@ -33,6 +33,7 @@ tar -xf "$OVERLAY" -O binutils/xtensa-modules.c | \
         -e '/^uint32 \*bypass_entry(int i)/,/}/d' \
         -e '/^#include "ansidecl.h"/d' \
         -e '/^Slot_[a-zA-Z0-9_]\+_decode (const xtensa_insnbuf insn)/,/^}/s/^  return 0;$/  return XTENSA_UNDEFINED;/' \
+        -e 's/#include <xtensa-isa.h>/#include "xtensa-isa.h"/' \
     > "$TARGET"/xtensa-modules.inc.c
 
 cat <<EOF > "${TARGET}.c"