target-arm: Rename QEMU PSCI v0.1 definitions

The function IDs for PSCI v0.1 are exported by KVM and defined as
KVM_PSCI_FN_<something>.  To build using these defines in non-KVM code,
QEMU defines these IDs locally and check their correctness against the
KVM headers when those are available.

However, the naming scheme used for QEMU (almost) clashes with the PSCI
v0.2 definitions from Linux so to avoid unfortunate naming when we
introduce local PSCI v0.2 defines, rename the current local defines with
QEMU_ prependend and clearly identify the PSCI version as v0.1 in the
defines.

Cc: qemu-stable@nongnu.org
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
