ARM: dts: Disable RPM notifications for L2 GDHS collapse on Krait targets

Entering vdd minimization is unsupported during L2 GDHS collapse.
Prevent this from happening by not notifying the RPM during the L2
GDHS SPM sequence.

CRs-Fixed: 609356
Change-Id: Iefcb3597df5af104f823fdfb1ad1879f5d1d057e
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>