external/mambo: add shortcut to print all GPRs
external/mambo: add shortcut to print all GPRs

The 'p' function added by mambo utils can be used to print registers
(GPR or SPR) from a thread. Mambo supports printing all the GPRs in one
go so this plumbs it into the 'p' function.

Signed-off-by: Oliver O'Halloran <3dfaff8fa6ae977f042064a112a6aac576279b9b@gmail.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

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