arm64/cpufeature: Add missing id_aa64mmfr4 feature reg update

Add missing id_aa64mmfr4 feature register check and update in
update_cpu_features(). Update the taint status as well.

Signed-off-by: Yicong Yang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

arch/arm64/kernel/cpufeature.c

···
 				      info->reg_id_aa64mmfr2, boot->reg_id_aa64mmfr2);
 	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR3_EL1, cpu,
 				      info->reg_id_aa64mmfr3, boot->reg_id_aa64mmfr3);
+	taint |= check_update_ftr_reg(SYS_ID_AA64MMFR4_EL1, cpu,
+				      info->reg_id_aa64mmfr4, boot->reg_id_aa64mmfr4);
 
 	taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
 				      info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);