Add HS toolchain to UcLibc plugin

1:haven't add options enablement
2:haven't done all HS options
3:Use arc-buildroot-linux-uclibc-xxx

19:05:12 **** Build of configuration Debug for project s ****
make all
Building file: ../src/crt0.S
Invoking: ARC Linux UcLibc GCC Assembler
arc-buildroot-linux-uclibc-gcc -x assembler-with-cpp -Wall -Wa,-adhlns="src/crt0.o.lst" -c -fmessage-length=0 -MMD -MP -MF"src/crt0.d" -MT"src/crt0.d" -mHS -g3 -gdwarf-2 -o "src/crt0.o" "../src/crt0.S"
Finished building: ../src/crt0.S

Building file: ../src/s.c
Invoking: ARC Linux UcLibc GCC C Compiler
arc-buildroot-linux-uclibc-gcc -O0 -Wall -Wa,-adhlns="src/s.o.lst" -c -fmessage-length=0 -MMD -MP -MF"src/s.d" -MT"src/s.d" -mHS -g3 -gdwarf-2 -o "src/s.o" "../src/s.c"
Finished building: ../src/s.c

Building target: s.elf
Invoking: ARC Linux UcLibc GCC C Linker
arc-buildroot-linux-uclibc-gcc -T"/home/yunluz/runtime-EclipseApplication/s/lds/arcelf.lds" -nostartfiles -Wl,-Map,s.map -mHS -g3 -gdwarf-2 -o "s.elf"  ./src/crt0.o ./src/s.o
Finished building target: s.elf

19:05:13 Build Finished (took 765ms)

Signed-off-by: Yunlu Zhang <Yunlu.Zhang@synopsys.com>