added TI$ and keybopard scanning constants for UP9600 interrupt rate

src/kernal/keyboard/scnkey.s

@@ -327,7 +327,11 @@ scnkey_got_key: // .Y should now contain the key offset in matrix pointed by KEY
 	//
 	// Besides - since I am the one who writes the code, I will make the values exactly how I like them :D
 
+#if !CONFIG_RS232_UP9600
 	lda #$16
+#else
+	lda #$18
+#endif
 	sta DELAY
 
 	// FALLTROUGH