hw/riscv/virt.c: use s->memmap in finalize_fdt() functions

hw/riscv/virt.c: use s->memmap in finalize_fdt() functions

Change create_fdt_pcie(), create_fdt_reset(), create_fdt_uart() and
create_fdt_rtc() to use s->memmap in their logic.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20250429125811.224803-9-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>