vibrator: Simplify soc check and drop prop dep

[npjohnson]: adapt to reflect 18.1 upstream merges as well as
include now required headers.

Change-Id: I8581d22deac451d0c44e4b3135d2729da2865a36

aidl/vibrator/VibratorOffload.cpp

@@ -45,10 +45,6 @@
 #include "include/Vibrator.h"
 #include "VibratorPatterns.h"
 
-extern "C" {
-#include "libsoc_helper.h"
-}
-
 namespace aidl {
 namespace android {
 namespace hardware {