efi: Add ESRT to the EFI system table

The ESRT is initialised during efi_init_objlist after
efi_initialize_system_table().

The ESRT is recreated from scratch at the following events:
- successful UpdateCapsule;
- FMP instance install.

The code ensures that every ESRT entry has a unique fw_class value.

Limitations:
- The ESRT is not updated if an FMP instance is uninstalled;
- the fields image_type and flags are in the current implementation left
undefined. Setting these values will require a per-platform function
that returns the image_type/flags as a function of the image fw_class.

CC: Heinrich Schuchardt	<xypron.glpk@gmx.de>
CC: Sughosh Ganu <sughosh.ganu@linaro.org>
CC: AKASHI Takahiro <takahiro.akashi@linaro.org>
CC: Ilias Apalodimas <ilias.apalodimas@linaro.org>
CC: Andre Przywara <andre.przywara@arm.com>
CC: Alexander Graf <agraf@csgraf.de>
CC: nd@arm.com
Signed-off-by: Jose Marinho <jose.marinho@arm.com>

Remove two EFI_CALL() indirections.
Move ESRT GUID in efidebug's list of GUIDs.

Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

include/efi_loader.h

@@ -214,6 +214,8 @@ extern const efi_guid_t efi_guid_rng_protocol;
 extern const efi_guid_t efi_guid_capsule_report;
 /* GUID of firmware management protocol */
 extern const efi_guid_t efi_guid_firmware_management_protocol;
+/* GUID for the ESRT */
+extern const efi_guid_t efi_esrt_guid;
 
 extern unsigned int __efi_runtime_start, __efi_runtime_stop;
 extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
@@ -559,6 +561,10 @@ struct efi_simple_file_system_protocol *efi_simple_file_system(
 /* open file from device-path: */
 struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp);
 
+/* Registers a callback function for a notification event. */
+efi_status_t EFIAPI efi_register_protocol_notify(const efi_guid_t *protocol,
+						 struct efi_event *event,
+						 void **registration);
 efi_status_t efi_file_size(struct efi_file_handle *fh, efi_uintn_t *size);
 
 /* get a device path from a Boot#### option */
@@ -902,4 +908,22 @@ static inline efi_status_t efi_launch_capsules(void)
 
 #endif /* CONFIG_IS_ENABLED(EFI_LOADER) */
 
+/**
+ * Install the ESRT system table.
+ *
+ * @return	status code
+ */
+efi_status_t efi_esrt_register(void);
+
+/**
+ * efi_esrt_populate() - Populates the ESRT entries from the FMP instances
+ * present in the system.
+ * If an ESRT already exists, the old ESRT is replaced in the system table.
+ * The memory of the old ESRT is deallocated.
+ *
+ * Return:
+ * - EFI_SUCCESS if the ESRT is correctly created
+ * - error code otherwise.
+ */
+efi_status_t efi_esrt_populate(void);
 #endif /* _EFI_LOADER_H */