AMD Fam10h: Only create _PR scope if it is filled in

The former pstates_algorithm() function has two early exit
points now, and so it might never get around to writing
pstates data.

Change-Id: I19ca937375c6d33b78bd5b1859fa5c25473be9b6
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/8610
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
2 files changed