applications: nrf_desktop: Fix enabling LTO

Missing dependencies in `CONFIG_LTO` default value overlay led to
build issues when disabling both LTO and ISR tables local declaration
using CLI arguments. Change fixes the build issues.

Jira: NCSDK-32238

Signed-off-by: Marek Pieta <[email protected]>

Author: MarekPieta

applications/nrf_desktop/Kconfig.defaults

@@ -22,12 +22,10 @@ choice LIBC_IMPLEMENTATION
 	  Use minimal libc implementation to reduce memory footprint.
 endchoice
 
-config LTO
-	default y
-	help
-	  nRF Desktop enables LTO to limit memory usage and improve performance.
-
-config ISR_TABLES_LOCAL_DECLARATION
+config DESKTOP_LTO_DEFAULTS
+	bool
 	default y
+	imply LTO
+	imply ISR_TABLES_LOCAL_DECLARATION
 	help
 	  nRF Desktop enables LTO to limit memory usage and improve performance.