feat(plat/mediatek/mt8195): improve SPM wakeup log

To enhance debug efficiency, modify wakeup log:
1. Redefine strings of wakeup reason for readability.
2. Indicate 26M clock on/off state of previous suspend.
3. Add warning log if SPM cannot get wakeup reason.

TEST=build pass

Signed-off-by: Edward-JW Yang <edward-jw.yang@mediatek.corp-partner.google.com>
Change-Id: Icb14ebb08958da225969abd3cdd9e471d232c7eb
1 file changed