hw/tpm: TIS on sysbus: Remove unsupport ppi command line option

hw/tpm: TIS on sysbus: Remove unsupport ppi command line option

The ppi command line option for the TIS device on sysbus never worked
and caused an immediate segfault. Remove support for it since it also
needs support in the firmware and needs testing inside the VM.

Reproducer with the ppi=on option passed:

qemu-system-aarch64 \
   -machine virt,gic-version=3 \
   -m 4G  \
   -nographic -no-acpi \
   -chardev socket,id=chrtpm,path=/tmp/mytpm1/swtpm-sock \
   -tpmdev emulator,id=tpm0,chardev=chrtpm \
   -device tpm-tis-device,tpmdev=tpm0,ppi=on
[...]
Segmentation fault (core dumped)

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20230713171955.149236-1-stefanb@linux.ibm.com
(cherry picked from commit 4c46fe2ed492f35f411632c8b5a8442f322bc3f0)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>