Fix up last backport

* lisp/org.el (org-export-backend-options): Add back removed
declare-function call.
* lisp/ob-awk.el (orgtbl-to-generic):
* lisp/ob-core.el (orgtbl-to-generic):
* lisp/ob-gnuplot.el (orgtbl-to-generic): Remove BACKEND argument from
declare-function calls.

The last backport added this argument to match orgtbl-to-generic's
signature in Emacs's version of Org, but the BACKEND argument to
orgtbl-to-generic was later removed in 9209aa3 (org-table: Use "ox.el"
internally for radio tables, 2014-08-24).

lisp/ob-awk.el

@@ -36,8 +36,7 @@
 (eval-when-compile (require 'cl))
 
 (declare-function org-babel-ref-resolve "ob-ref" (ref))
-(declare-function orgtbl-to-generic "org-table"
-                  (table params &optional backend))
+(declare-function orgtbl-to-generic "org-table" (table params))
 
 (defvar org-babel-tangle-lang-exts)
 (add-to-list 'org-babel-tangle-lang-exts '("awk" . "awk"))

lisp/ob-core.el

@@ -77,8 +77,7 @@
 		  (hook function &optional append local))
 (declare-function org-table-align "org-table" ())
 (declare-function org-table-end "org-table" (&optional table-type))
-(declare-function orgtbl-to-generic "org-table"
-                  (table params &optional backend))
+(declare-function orgtbl-to-generic "org-table" (table params))
 (declare-function orgtbl-to-orgtbl "org-table" (table params))
 (declare-function org-babel-tangle-comment-links "ob-tangle" (&optional info))
 (declare-function org-babel-lob-get-info "ob-lob" nil)

lisp/ob-gnuplot.el

@@ -43,8 +43,7 @@
 
 (declare-function org-time-string-to-time "org" (s &optional buffer pos))
 (declare-function org-combine-plists "org" (&rest plists))
-(declare-function orgtbl-to-generic "org-table"
-                  (table params &optional backend))
+(declare-function orgtbl-to-generic "org-table" (table params))
 (declare-function gnuplot-mode "ext:gnuplot-mode" ())
 (declare-function gnuplot-send-string-to-gnuplot "ext:gnuplot-mode" (str txt))
 (declare-function gnuplot-send-buffer-to-gnuplot "ext:gnuplot-mode" ())

lisp/org.el

@@ -12320,6 +12320,7 @@ This function can be used in a hook."
 
 ;;;; Completion
 
+(declare-function org-export-backend-options "ox" (cl-x) t)
 (defun org-get-export-keywords ()
   "Return a list of all currently understood export keywords.
 Export keywords include options, block names, attributes and