trusty: keymint: rename trusty_ipc_dev property

matching the naming convention for a system service property

Bug: 309007107
Test: launch_cvd --noresume --console=true \
      --extra_kernel_cmdline='androidboot.selinux=permissive' \
      --secure_hals=guest_keymint_trusty_insecure
Change-Id: I7c31f36dcac49d60469de44ce75c9b46a333786e