[ramdisk] add cvitek pre-built ramdisk

Change-Id: Ic7d2046a23358129eaf621b5558984a64fa7361d

ramdisk/initramfs/glibc_riscv64/usr/include/linux/signal.h

@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _LINUX_SIGNAL_H
+#define _LINUX_SIGNAL_H
+
+#include <asm/signal.h>
+#include <asm/siginfo.h>
+
+#define SS_ONSTACK	1
+#define SS_DISABLE	2
+
+/* bit-flags */
+#define SS_AUTODISARM	(1U << 31)	/* disable sas during sighandling */
+/* mask for all SS_xxx flags */
+#define SS_FLAG_BITS	SS_AUTODISARM
+
+#endif /* _LINUX_SIGNAL_H */