clean interface for sub-drivers wrt backlight, contrast and brightness

server/drivers/hd44780-ftdi.h

@@ -7,8 +7,4 @@
 // initialise this particular driver
 int hd_init_ftdi(Driver *drvthis);
 
-void ftdi_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char flags, unsigned char ch);
-void ftdi_HD44780_backlight(PrivateData *p, unsigned char state);
-void ftdi_HD44780_close(PrivateData *p);
-
 #endif