doc: release: 2.7: remove duplicate IPM entry

Remove duplicate IPM entry.

Signed-off-by: Christopher Friedt <[email protected]>

Author: cfriedt

doc/releases/release-notes-2.7.rst

@@ -427,15 +427,11 @@ Drivers and Sensors
 
 * IPM
 
-  * Added STM32 HSEM IPM driver.
+  * STM32: Add HSEM based IPM driver for STM32H7 series
 
 * Interrupt Controller
 
 
-* IPM
-
-  * STM32: Add HSEM based IPM driver for STM32H7 series
-
 * LED