efi/libstub: Add libstub/mem.c to the documentation tree

Let the description of the efi/libstub/mem.c functions appear in the kernel
API documentation in the following chapters:

    The Linux driver implementer’s API guide
        Linux Firmware API
            UEFI Support
                UEFI stub library functions

Acked-by: Jonathan Corbet <[email protected]>
Signed-off-by: Heinrich Schuchardt <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Link: https://lore.kernel.org/r/[email protected]

Author: xypron

Documentation/driver-api/firmware/efi/index.rst

@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============
+UEFI Support
+============
+
+UEFI stub library functions
+===========================
+
+.. kernel-doc:: drivers/firmware/efi/libstub/mem.c
+   :internal:

Documentation/driver-api/firmware/index.rst

@@ -6,6 +6,7 @@ Linux Firmware API
 
    introduction
    core
+   efi/index
    request_firmware
    other_interfaces