docs/ad9088: Fix UG-2326 link

The link was pointing to an invalid target.

Signed-off-by: Uicentiu Ueagoe <vicentiu.neagoe@analog.com>

Author: vicentiu2

docs/drivers/iio-trx-rf/ad9088/index.rst

@@ -35,7 +35,7 @@ Evaluation Boards
 -----------------
 
 * | :adi:`EVAL-AD9084`
-  | :adi:`User Guide (UG-2326) <media/en/technical-documentation/user-guides/eval-ad9084-ug-2326.pdf>`
+  | :adi:`User Guide (UG-2326) <media/en/technical-documentation/user-guides/eval-ad9084-ad9088-ug-2326.pdf>`
 
 Source Code
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