rename FREERTOS_PORT to FREERTOS_PORTABLE_SRC

also fix trailing spaces

hw/bsp/lpc15/family.mk

@@ -12,7 +12,7 @@ CFLAGS += \
   -D__USE_LPCOPEN \
   -DCFG_EXAMPLE_MSC_READONLY \
   -DCFG_TUSB_MCU=OPT_MCU_LPC15XX \
-  -DCFG_TUSB_MEM_ALIGN='__attribute__((aligned(64)))' 
+  -DCFG_TUSB_MEM_ALIGN='__attribute__((aligned(64)))'
 
 # mcu driver cause following warnings
 CFLAGS += -Wno-error=strict-prototypes -Wno-error=unused-parameter -Wno-error=unused-variable -Wno-error=cast-qual
@@ -36,4 +36,4 @@ INC += \
 	$(TOP)/$(MCU_DIR)/inc
 
 # For freeRTOS port source
-FREERTOS_PORT = $(FREERTOS_PORT_PATH)/ARM_CM3
+FREERTOS_PORTABLE_SRC = $(FREERTOS_PORTABLE_PATH)/ARM_CM3