target/riscv: Add ePMP support for the Ibex CPU

The physical Ibex CPU has ePMP support and it's enabled for the
OpenTitan machine so let's enable ePMP support for the Ibex CPU in QEMU.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: d426baabab0c9361ed2e989dbe416e417a551fd1.1618812899.git.alistair.francis@wdc.com

target/riscv/cpu.c

@@ -202,6 +202,7 @@ static void rv32_ibex_cpu_init(Object *obj)
     set_misa(env, RV32 | RVI | RVM | RVC | RVU);
     set_priv_version(env, PRIV_VERSION_1_10_0);
     qdev_prop_set_bit(DEVICE(obj), "mmu", false);
+    qdev_prop_set_bit(DEVICE(obj), "x-epmp", true);
 }
 
 static void rv32_imafcu_nommu_cpu_init(Object *obj)