lscpu: Add loongarch testcase

Signed-off-by: Xi Ruoyao <xry111@xry111.site>

tests/expected/lscpu/lscpu-loongarch-loongson_3a5000_hv

@@ -0,0 +1,37 @@
+CPU op-mode(s):      32-bit, 64-bit
+Address sizes:       48 bits physical, 48 bits virtual
+Byte Order:          Little Endian
+CPU(s):              4
+On-line CPU(s) list: 0-3
+Model name:          Loongson-3A5000-HV
+CPU family:          Loongson-64bit
+Model:               0x11
+Thread(s) per core:  1
+Core(s) per socket:  4
+Socket(s):           1
+BogoMIPS:            5000.00
+Flags:               cpucfg lam ual fpu lsx lasx complex crypto lvz
+L1d cache:           256 KiB (4 instances)
+L1i cache:           256 KiB (4 instances)
+L2 cache:            1 MiB (4 instances)
+L3 cache:            16 MiB (1 instance)
+NUMA node(s):        1
+NUMA node0 CPU(s):   0-3
+
+# The following is the parsable format, which can be fed to other
+# programs. Each different item in every column has an unique ID
+# starting usually from zero.
+# CPU,Core,Socket,Node,,L1d,L1i,L2,L3
+0,0,0,0,,0,0,0,0
+1,1,0,0,,1,1,1,0
+2,2,0,0,,2,2,2,0
+3,3,0,0,,3,3,3,0
+
+# The following is the parsable format, which can be fed to other
+# programs. Each different item in every column has an unique ID
+# starting usually from zero.
+# CPU,Core,Socket,Node,,L1d,L1i,L2,L3
+0,0,0,0,,0,0,0,0
+1,1,0,0,,1,1,1,0
+2,2,0,0,,2,2,2,0
+3,3,0,0,,3,3,3,0