hw/riscv: Select MSI_NONBROKEN in SIFIVE_PLIC

hw/riscv: Select MSI_NONBROKEN in SIFIVE_PLIC

hw/pci/Kconfig says MSI_NONBROKEN should be selected by interrupt
controllers regardless of how MSI is implemented. msi_nonbroken is
initialized to true in sifive_plic_realize().

Let SIFIVE_PLIC select MSI_NONBROKEN and drop the selection from
RISC-V machines.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Message-Id: <20221211030829.802437-1-bmeng@tinylab.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>