platform: Call generic platform probe and init UART there
platform: Call generic platform probe and init UART there

At the moment the generic platform initializes the UART really late,
which make debugging harder than it needs to be. Most platforms set
it up in their probe() callback but the generic platform doesn't have
one.

This adds one and initializes the UART in it.

Signed-off-by: Benjamin Herrenschmidt <a7089bb6e7e92505d88aaff006cbdd60cc9120b6@kernel.crashing.org>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

shenki/skiboot,open-power/skiboot,mikey/skiboot,shenki/skiboot,qemu/skiboot,legoater/skiboot,shenki/skiboot,legoater/skiboot,open-power/skiboot,shenki/skiboot,stewart-ibm/skiboot,qemu/skiboot,qemu/skiboot,qemu/skiboot,open-power/skiboot,mikey/skiboot,legoater/skiboot,mikey/skiboot,legoater/skiboot,legoater/skiboot,qemu/skiboot,shenki/skiboot,open-power/skiboot,stewart-ibm/skiboot,open-power/skiboot,stewart-ibm/skiboot