[kernel] Make sure to virtualize ACPI table pointers

Probably due to old UEFI page tables going away, some systems failed to
load ACPI tables at their physical location. Make sure to translate them
to kernel offset-mapped addresses.

src/kernel/acpi_tables.h

@@ -23,7 +23,7 @@ struct acpi_table_header
 } __attribute__ ((packed));
 
 #define TABLE_HEADER(signature) \
-	static const uint32_t type_id = kutil::byteswap(signature); \
+	static constexpr uint32_t type_id = kutil::byteswap(signature); \
 	acpi_table_header header;