fix build error with new sdk

bsp/k210/rtconfig.py

@@ -38,8 +38,8 @@ if PLATFORM == 'gcc':
     OBJDUMP = PREFIX + 'objdump'
     OBJCPY  = PREFIX + 'objcopy'
 
-    DEVICE  = ' -mcmodel=medany'
-    CFLAGS  = DEVICE + ' -fno-common -ffunction-sections -fdata-sections -fstrict-volatile-bitfields '
+    DEVICE  = ' -mcmodel=medany -march=rv64imafdc -mabi=lp64d'
+    CFLAGS  = DEVICE + ' -fno-common -ffunction-sections -fdata-sections -fstrict-volatile-bitfields'
     AFLAGS  = ' -c' + DEVICE + ' -x assembler-with-cpp'
     LFLAGS  = DEVICE + ' -nostartfiles -Wl,--gc-sections,-Map=rtthread.map,-cref,-u,_start -T link.lds'
     CPATH   = ''