[bsp][synopsys] add the support of synopsys arc emsk

* the initial support of synopsys designware arc processor
* the initial support of synospsy ARC EM Starter Kit
* the bsp code is based on embarc which is a common SDK for
all synopsys ARC-based boards
* use "scons --gdb" to debug emsk with em9d configuration
* for detailed board information, pls go embarc.org

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>

bsp/synopsys/embarc/SConscript

@@ -0,0 +1,28 @@
+from building import *
+
+cwd = GetCurrentDir()
+
+embarc_arc_hal_SRCS = Split("""
+arc/arc_cache.c
+arc/arc_exc_asm.S
+arc/arc_exception.c
+arc/arc_timer.c
+arc/startup/arc_cxx_support.c
+arc/startup/arc_startup.S
+device/designware/uart/dw_uart.c
+device/designware/gpio/dw_gpio.c
+""")
+
+
+ASFLAGS = ' -I' + cwd
+
+src = embarc_arc_hal_SRCS
+
+path = [cwd,
+	cwd + '/arc',
+	cwd + '/arc/startup'
+	]
+
+group = DefineGroup('embarc', src, depend = [], CPPPATH = path, ASFLAGS = ASFLAGS)
+
+Return('group')