grove: fix variable type mismatch

These were reported by ISSM compiler.

Jira: ZEP-1179

Change-Id: I10d04c2949ad2a390d4c1159d2342c73108a58b7
Signed-off-by: Jithu Joseph <[email protected]>

Author: jithu83

drivers/grove/lcd_rgb.c

@@ -112,7 +112,7 @@ static inline void _sleep(uint32_t sleep_in_ms)
 /********************************************
  *  PUBLIC FUNCTIONS
  *******************************************/
-void glcd_print(struct device *port, unsigned char *data, uint32_t size)
+void glcd_print(struct device *port, char *data, uint32_t size)
 {
 	const struct glcd_driver * const rom = (struct glcd_driver *)
 						port->config->config_info;

include/display/grove_lcd.h

@@ -30,7 +30,7 @@ extern "C" {
  *  @param data the ASCII text to display
  *  @param size the length of the text in bytes
  */
-void glcd_print(struct device *port, unsigned char *data, uint32_t size);
+void glcd_print(struct device *port, char *data, uint32_t size);
 
 
 /**