ARM: dts: qcom: remove pc-save and round-robin entries on 8994

Remove pc-save and round-robin entries from ETM dt nodes since
these are not applicable for 8994 which uses Cortex A53 and A57
processors.

Change-Id: I92de6452ff2f368ed5816b586c1ae265b679ada8
Signed-off-by: Pratik Patel <pratikp@codeaurora.org>