[Qemu-ppc] Command key in QEMU

[Programmingkid]

I have thought a way for the command key to work in QEMU. This method will 
allow the user to decide which key they want to designate as the command key. 
An option can be added to QEMU that allows the user to set the command key 
using a hexadecimal code like this: qemu-system-ppc -command-key 0x37. 

There are a lot of different keyboards out in the world. Not only do we have to 
consider the keyboards that use ascii keys, but we also need to consider 
keyboards that use non-ascii keys. There are chinese, japanese, telugu, 
russian, and other keyboards that are made by a lot of different companies for 
different systems. Their lettering and layout might be different, but they all 
use a value to specify a key. By using a value, we could have any key on the 
keyboard be the command key. A user can have one of the function keys act as 
the command key if desired. 

If there are no issues, I will start on a patch.