add raspi2 and raspi3 BSP

bsp/raspberry-pi/raspi3-64/driver/SConscript

@@ -0,0 +1,32 @@
+# RT-Thread building script for component
+
+from building import *
+
+cwd     = GetCurrentDir()
+src     = Split('''
+board.c
+bcm283x.c
+drv_uart.c
+mbox.c
+''')
+CPPPATH = [cwd]
+
+if GetDepend('BSP_USING_SYSTIMER'):
+    src += ['drv_timer.c']
+if GetDepend('BSP_USING_PIN'):
+    src += ['drv_gpio.c']
+if GetDepend('BSP_USING_I2C'):
+    src += ['drv_i2c.c']
+if GetDepend('BSP_USING_WDT'):
+    src += ['drv_wdt.c']
+if GetDepend('BSP_USING_SPI'):
+    src += ['drv_spi.c']
+if GetDepend('BSP_USING_SDIO'):
+    src += ['drv_sdio.c']
+if GetDepend('BSP_USING_RTC'):
+    src += ['drv_rtc.c']
+if GetDepend('BSP_USING_HDMI'):
+    src += ['drv_fb.c']
+group = DefineGroup('Drivers', src, depend = [''], CPPPATH = CPPPATH)
+
+Return('group')