spapr: Merge sPAPREnvironment into sPAPRMachineState

spapr: Merge sPAPREnvironment into sPAPRMachineState

The code for -machine pseries maintains a global sPAPREnvironment structure
which keeps track of general state information about the guest platform.
This predates the existence of the MachineState structure, but performs
basically the same function.

Now that we have the generic MachineState, fold sPAPREnvironment into
sPAPRMachineState, the pseries specific subclass of MachineState.

This is mostly a matter of search and replace, although a few places which
relied on the global spapr variable are changed to find the structure via
qdev_get_machine().

Signed-off-by: David Gibson <[email protected]>
Signed-off-by: Alexander Graf <[email protected]>