Ariane v0.7 pmu

[iJeremyLi]

Add support for Ariane's PMU(controlled with macro CONFIG_ARIANE_PMU)
There are some dependences in ariane-sdk

1. Need to add one sbi trap entry with id 9 and one param of Performance counter csr register's address offset.
2. Need to set
   BR2_PACKAGE_LINUX_TOOLS_PERF=y
   BR2_PACKAGE_LINUX_TOOLS_PERF_TUI=y
   int buildroot_defconfig
3. Need to use defconfig for kernel with arch/riscv/configs/ariane_defconfig

Now, You can use perf with stat/record/report/list/top subcommands.