Make LCD code working. Add FSM for LCD in order to write it in mainloop

stm-firmware/include/reflow-controller/ui/lcd.h

@@ -31,4 +31,14 @@
 #define	LCD_RS_MASK		(1U << LCD_RS)
 #define	LCD_E_MASK		(1U << LCD_E)
 
+enum lcd_fsm_ret {LCD_FSM_NOP, LCD_FSM_CALL_AGAIN, LCD_FSM_WAIT_CALL};
+
+void lcd_init(void);
+
+void lcd_string(const char *data);
+
+void lcd_home(void);
+
+enum lcd_fsm_ret lcd_fsm_write_buffer(const char (*display_buffer)[21]);
+
 #endif /* __LCD_H__ */