Revert "Update to v5.18 kernel headers."

Revert "Update to v5.18 kernel headers."

Revert submission 2106847-kernel_update

Reason for revert: b/234125620
Reverted Changes:
I5844ca1fc:Update to v5.18 kernel headers.
I5700813ee:Update to v5.18 kernel headers.
Bug: 234125620

Change-Id: I07a39aa9c01939455b5a2a9da5fc04be497ca399
diff --git a/libc/kernel/uapi/linux/rtc.h b/libc/kernel/uapi/linux/rtc.h
index d75bc45..cf5f22a 100644
--- a/libc/kernel/uapi/linux/rtc.h
+++ b/libc/kernel/uapi/linux/rtc.h
@@ -96,8 +96,7 @@
 #define RTC_FEATURE_UPDATE_INTERRUPT 4
 #define RTC_FEATURE_CORRECTION 5
 #define RTC_FEATURE_BACKUP_SWITCH_MODE 6
-#define RTC_FEATURE_ALARM_WAKEUP_ONLY 7
-#define RTC_FEATURE_CNT 8
+#define RTC_FEATURE_CNT 7
 #define RTC_PARAM_FEATURES 0
 #define RTC_PARAM_CORRECTION 1
 #define RTC_PARAM_BACKUP_SWITCH_MODE 2