riscv: sim.cc: Parse for "sifive,plic-1.0.0" if "riscv,plic0" is absent

"riscv,plic0" and "sifive,plic-1.0.0" in device tree's "compatible" string point to the same driver,
as can be seen from drivers/irqchip/irq-sifive-plic.c in Linux kernel.
https://github.com/torvalds/linux/commit/5873ba559101fa37ad9764e79856f71bf54021aa


The other two "compatible" strings below isn't included,
because of their different plic behavior (plic_edge_init instead of plic_init as explained in the Linux commit).
- "andestech,nceplic100"
- "thead,c900-plic"

Signed-off-by: Tan En De <ende.tan@starfivetech.com>