Add dump of panel power_mode.

Add the power_mode sysfs node to dump_second_display.cpp and
dump_display.cpp.

Bug: 358505990
Flag: EXEMPT bugfix
Test: adb bugreport.
Change-Id: I875b9a3ef416c188376eb2f9226996b6645ccdb9
Signed-off-by: attis <attis@google.com>
2 files changed