[BSP] Update stm32f7-disco to avoid gcc compiling error

bsp/stm32f7-disco/rtconfig.h

@@ -116,7 +116,7 @@
 // <bool name="RT_USING_LIBC" description="Using libc library" default="true" />
 #define RT_USING_LIBC
 // <bool name="RT_USING_PTHREADS" description="Using POSIX threads library" default="true" />
-//#define RT_USING_PTHREADS
+#define RT_USING_PTHREADS
 // </section>
 
 // <section name="RT_USING_DFS" description="Device file system" default="true" >

bsp/stm32f7-disco/rtconfig.py

@@ -40,7 +40,7 @@ if PLATFORM == 'gcc':
     OBJDUMP = PREFIX + 'objdump'
     OBJCPY = PREFIX + 'objcopy'
 
-    DEVICE = '  -mcpu=cortex-m7 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=hard -ffunction-sections -fdata-sections'
+    DEVICE = '  -mcpu=cortex-m7 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=softfp -ffunction-sections -fdata-sections'
     CFLAGS = DEVICE + ' -g -Wall -DSTM32F756xx -DUSE_HAL_DRIVER -D__ASSEMBLY__ -D__FPU_USED'
     AFLAGS = ' -c' + DEVICE + ' -x assembler-with-cpp -Wa,-mimplicit-it=thumb '
     LFLAGS = DEVICE + ' -lm -lgcc -lc' + ' -nostartfiles -Wl,--gc-sections,-Map=rtthread_stm32f7xx.map,-cref,-u,Reset_Handler -T rtthread-stm32f7xx.ld'