add --specs=nosys.specs to prevent build errors, update mbed core

Author: Wenn0101

cores/mbed-os

@@ -46,7 +46,7 @@ compiler.preproc.flags={compiler.cxx.flags} -w -x c++ -E -CC {compiler.preproc.e
 compiler.asm.flags=-include "{build.variant.path}/mbed/mbed_config.h" -iprefix "{runtime.platform.path}/cores/" "@{build.variant.path}/mbed/.asm-flags" {compiler.asm.extra_flags}
 compiler.c.flags=-iprefix "{runtime.platform.path}/cores/" "@{build.variant.path}/mbed/.c-flags" {compiler.c.extra_flags}
 compiler.cxx.flags=-include "{build.variant.path}/mbed/mbed_config.h" -include "{cores.path}/arduino/sdk/ArduinoSDK.h" -iprefix "{runtime.platform.path}/cores/" "@{build.variant.path}/mbed/.cxx-flags" {compiler.cxx.extra_flags}
-compiler.ld.flags="@{build.variant.path}/mbed/.ld-flags" {compiler.ld.extra_flags} --specs=nano.specs -lsupc++ -lstdc++ -lm
+compiler.ld.flags="@{build.variant.path}/mbed/.ld-flags" {compiler.ld.extra_flags} --specs=nano.specs --specs=nosys.specs -lsupc++ -lstdc++ -lm
 compiler.ar.flags=rcsP {compiler.ar.extra_flags} {compiler.ar.extra_flags}
 compiler.axf2bin.flags={compiler.axf2bin.extra_flags} {compiler.axf2bin.extra_flags} -O binary
 compiler.axf2hex.flags={compiler.axf2hex.extra_flags} {compiler.axf2hex.extra_flags} -O ihex