Add NT_ARM_TAGGED_ADDR_CTRL from Linux 5.10 to elf.h.

This patch adds the new NT_ARM_TAGGED_ADDR_CTRL constant from Linux
5.10 to glibc's elf.h.

Tested for x86_64.

elf/elf.h

@@ -813,6 +813,8 @@ typedef struct
 					   address keys.  */
 #define NT_ARM_PACG_KEYS	0x408	/* ARM pointer authentication
 					   generic key.  */
+#define NT_ARM_TAGGED_ADDR_CTRL	0x409	/* AArch64 tagged address
+					   control.  */
 #define NT_VMCOREDD	0x700		/* Vmcore Device Dump Note.  */
 #define NT_MIPS_DSP	0x800		/* MIPS DSP ASE registers.  */
 #define NT_MIPS_FP_MODE	0x801		/* MIPS floating-point mode.  */