patch 8.2.3864: cannot disable requesting key codes from xterm

Problem:    Cannot disable requesting key codes from xterm.
Solution:   Add the 'xtermcodes' option, default on.
diff --git a/src/option.h b/src/option.h
index 49d869b..a82258e 100644
--- a/src/option.h
+++ b/src/option.h
@@ -485,6 +485,7 @@
 #ifdef FEAT_EVAL
 EXTERN char_u	*p_ccv;		// 'charconvert'
 #endif
+EXTERN int	p_cdh;		// 'cdhome'
 EXTERN char_u	*p_cino;	// 'cinoptions'
 #ifdef FEAT_CMDWIN
 EXTERN char_u	*p_cedit;	// 'cedit'
@@ -1094,7 +1095,7 @@
 EXTERN int	p_wa;		// 'writeany'
 EXTERN int	p_wb;		// 'writebackup'
 EXTERN long	p_wd;		// 'writedelay'
-EXTERN int	p_cdh;		// 'cdhome'
+EXTERN int	p_xtermcodes;	// 'xtermcodes'
 
 /*
  * "indir" values for buffer-local options.