refactor: IBRS_ALL & RDCL_NO are Intel-only

spectre-meltdown-checker.sh

@@ -1587,6 +1587,7 @@ check_cpu()
 		fi
 	fi
 
+	if is_intel; then
 		_info     "  * Enhanced IBRS (IBRS_ALL)"
 		_info_nol "    * CPU indicates ARCH_CAPABILITIES MSR availability: "
 		cpuid_arch_capabilities=-1
@@ -1668,6 +1669,7 @@ check_cpu()
 		else
 			pstatus yellow NO
 		fi
+	fi
 
 	_info_nol "  * CPU microcode is known to cause stability problems: "
 	if is_ucode_blacklisted; then