LoongArch: Add qspinlock support

On NUMA system, the performance of qspinlock is better than generic
spinlock. Below is the UnixBench test results on a 8 nodes (4 cores
per node, 32 cores in total) machine.

A. With generic spinlock:

System Benchmarks Index Values BASELINE RESULT INDEX
Dhrystone 2 using register variables 116700.0 449574022.5 38523.9
Double-Precision Whetstone 55.0 85190.4 15489.2
Execl Throughput 43.0 14696.2 3417.7
File Copy 1024 bufsize 2000 maxblocks 3960.0 143157.8 361.5
File Copy 256 bufsize 500 maxblocks 1655.0 37631.8 227.4
File Copy 4096 bufsize 8000 maxblocks 5800.0 444814.2 766.9
Pipe Throughput 12440.0 5047490.7 4057.5
Pipe-based Context Switching 4000.0 2021545.7 5053.9
Process Creation 126.0 23829.8 1891.3
Shell Scripts (1 concurrent) 42.4 33756.7 7961.5
Shell Scripts (8 concurrent) 6.0 4062.9 6771.5
System Call Overhead 15000.0 2479748.6 1653.2
========
System Benchmarks Index Score 2955.6

B. With qspinlock:

System Benchmarks Index Values BASELINE RESULT INDEX
Dhrystone 2 using register variables 116700.0 449467876.9 38514.8
Double-Precision Whetstone 55.0 85174.6 15486.3
Execl Throughput 43.0 14769.1 3434.7
File Copy 1024 bufsize 2000 maxblocks 3960.0 146150.5 369.1
File Copy 256 bufsize 500 maxblocks 1655.0 37496.8 226.6
File Copy 4096 bufsize 8000 maxblocks 5800.0 447527.0 771.6
Pipe Throughput 12440.0 5175989.2 4160.8
Pipe-based Context Switching 4000.0 2207747.8 5519.4
Process Creation 126.0 25125.5 1994.1
Shell Scripts (1 concurrent) 42.4 33461.2 7891.8
Shell Scripts (8 concurrent) 6.0 4024.7 6707.8
System Call Overhead 15000.0 2917278.6 1944.9
========
System Benchmarks Index Score 3040.1

Signed-off-by: Rui Wang <wangrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>