[Bsp][F7-Disco]fix startup by gcc

bsp/stm32f7-disco/Libraries/CMSIS/Device/ST/STM32F7xx/Source/Templates/gcc/startup_stm32f745xx.s

@@ -110,9 +110,9 @@ LoopFillZerobss:
 /* Call the clock system initialization function.*/
   bl  SystemInit   
 /* Call static constructors */
-    bl __libc_init_array
+/*    bl __libc_init_array */
 /* Call the application's entry point.*/
-  bl  main
+  bl  entry
   bx  lr    
 .size  Reset_Handler, .-Reset_Handler
 

bsp/stm32f7-disco/Libraries/CMSIS/Device/ST/STM32F7xx/Source/Templates/gcc/startup_stm32f746xx.s

@@ -110,9 +110,9 @@ LoopFillZerobss:
 /* Call the clock system initialization function.*/
   bl  SystemInit   
 /* Call static constructors */
-    bl __libc_init_array
+/*    bl __libc_init_array */
 /* Call the application's entry point.*/
-  bl  main
+  bl  entry
   bx  lr    
 .size  Reset_Handler, .-Reset_Handler
 

bsp/stm32f7-disco/Libraries/CMSIS/Device/ST/STM32F7xx/Source/Templates/gcc/startup_stm32f756xx.s

@@ -110,9 +110,9 @@ LoopFillZerobss:
 /* Call the clock system intitialization function.*/
   bl  SystemInit   
 /* Call static constructors */
-    bl __libc_init_array
+/*    bl __libc_init_array */
 /* Call the application's entry point.*/
-  bl  main
+  bl  entry
   bx  lr    
 .size  Reset_Handler, .-Reset_Handler