[libcpu] mips: Merge loongson_1 into gs232

Previously Loongson 1B and Loongson 1C have their own libcpu
implemention, but they're almost identical. So we merge them
into gs232 and adapt to new common code.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>

libcpu/mips/gs232/SConscript

@@ -0,0 +1,14 @@
+# RT-Thread building script for component
+
+from building import *
+
+Import('rtconfig')
+
+cwd     = GetCurrentDir()
+src     = Glob('*.c') + Glob('*.cpp') + Glob('*_gcc.S')
+CPPPATH = [cwd]
+ASFLAGS = ''
+
+group = DefineGroup('cpu', src, depend = [''], CPPPATH = CPPPATH, ASFLAGS = ASFLAGS)
+
+Return('group')