docs: fix hard coded target name in essl doc
@@ -176,7 +176,7 @@ counter.
Application Example
-------------------
-The example below shows how ESP32 SDIO host and slave communicate with each other. The host use the ESSL SDIO.
+The example below shows how {IDF_TARGET_NAME} SDIO host and slave communicate with each other. The host use the ESSL SDIO.
:example:`peripherals/sdio`.
