rpi4: enable RPi4 PCI SMC conduit

Now that we have adjusted the address map, added the
SMC conduit code, and the RPi4 PCI callbacks, lets
add the flags to enable everything in the build.

By default this service is disabled because the
expectation is that its only useful in a UEFI+ACPI
environment.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Change-Id: I2a3cac6d63ba8119d3b711db121185816b89f8a2
1 file changed