doc: FIT links in develop/uefi/uefi.rst

Correct the links to the FIT documentation.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/doc/develop/uefi/uefi.rst b/doc/develop/uefi/uefi.rst
index 0389b26..ea70dcb 100644
--- a/doc/develop/uefi/uefi.rst
+++ b/doc/develop/uefi/uefi.rst
@@ -72,7 +72,7 @@
 
     CONFIG_BOOTM_EFI=y
 
-A sample configuration is provided as file doc/uImage.FIT/uefi.its.
+A sample configuration is provided in :doc:`../../usage/fit/uefi`.
 
 Below you find the output of an example session starting GRUB::
 
@@ -96,7 +96,7 @@
     ## Transferring control to EFI (at address 404000d0) ...
     Welcome to GRUB!
 
-See doc/uImage.FIT/howto.txt for an introduction to FIT images.
+See :doc:`../../usage/fit/howto` for an introduction to FIT images.
 
 Configuring UEFI secure boot
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~