Record acpi_sdt_hdr

struct acpi_sdt_hdr {
  uacpi_char[4] signature;
  uacpi_u32 length;
  uacpi_u8 revision;
  uacpi_u8 checksum;
  uacpi_char[6] oemid;
  uacpi_char[8] oem_table_id;
  uacpi_u32 oem_revision;
  uacpi_u32 creator_id;
  uacpi_u32 creator_revision;
  /* Full declaration omitted */ 
}