feat(fake_host): add stub for xlat_enable_mmu_el2

This patch adds a stub for xlat_enable_mmu_el2 for the
for fake_host architecture.

Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: I7bf846bb02ca65b292a33254574f420409735799
diff --git a/plat/host/common/src/host_utils.c b/plat/host/common/src/host_utils.c
index 99fc708..8b0b08e 100644
--- a/plat/host/common/src/host_utils.c
+++ b/plat/host/common/src/host_utils.c
@@ -173,6 +173,9 @@
 	/* SCTLR_EL2 is reset to zero */
 	ret = host_util_set_default_sysreg_cb("sctlr_el2", 0UL);
 
+	/* HCR_EL2 is reset to zero */
+	ret = host_util_set_default_sysreg_cb("hcr_el2", 0UL);
+
 	/* TPIDR_EL2 is reset to zero */
 	ret = host_util_set_default_sysreg_cb("tpidr_el2", 0UL);