arm64/kernel: enable A53 erratum #8434319 handling at runtime

Omit patching of ADRP instruction at module load time if the current
CPUs are not susceptible to the erratum.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
[will: Drop duplicate initialisation of .def_scope field]
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/kernel/module.c

@@ -203,6 +203,7 @@ static int reloc_insn_adrp(struct module *mod, __le32 *place, u64 val)
 	u32 insn;
 
 	if (!IS_ENABLED(CONFIG_ARM64_ERRATUM_843419) ||
+	    !cpus_have_const_cap(ARM64_WORKAROUND_843419) ||
 	    ((u64)place & 0xfff) < 0xff8)
 		return reloc_insn_imm(RELOC_OP_PAGE, place, val, 12, 21,
 				      AARCH64_INSN_IMM_ADR);