plic: handle renumbered harts

[mhorne]

Summary

RISC-V harts may be renumbered during boot depending on the system's
configuration. For example, on the Hifive Unleashed hart 0 is a monitor
hart that never enters supervisor mode. Record the mapping of cpuid to
hart number, so that we can use the original hart value for cases where
they are not 1-to-1.

[br]

hart ID is recorded to pcpup->pc_hart. Could it be used ? i.e. PCPU_GET(hart) or pcpu_find(cpu)->pc_hart

[mhorne]

In D21940#479242, @br wrote:

hart ID is recorded to pcpup->pc_hart. Could it be used ? i.e. PCPU_GET(hart) or pcpu_find(cpu)->pc_hart

Thanks, this is what I wanted but I had trouble finding the right function for it. I'll update it later this evening to use this instead.

[mhorne]

This is now irrelevant after the rework of D21927.