M487: Remove unused variable 'u32EscapeFrame'

Remove unused variable 'u32EscapeFrame' in BSP m480_ccap.h to avoid warnings

Author: ccli8

targets/TARGET_NUVOTON/TARGET_M480/device/StdDriver/inc/m480_ccap.h

@@ -83,7 +83,6 @@ extern "C"
 #define CCAP_INT_MDIEN_ENABLE       (0x1ul<<CCAP_INT_MDIEN_Pos)       /*!< VININT setting for Motion Detection Output Finish Interrupt Enable enable  \hideinitializer */
 
 
-static uint32_t u32EscapeFrame = 0;
 /*---------------------------------------------------------------------------------------------------------*/
 /*  Define Error Code                                                                                      */
 /*---------------------------------------------------------------------------------------------------------*/