applications: nrf_desktop: Reduce nRF54H20DK debug cfg memory footprint

Switched from speed to size optimization for nRF54H20 DK target in
debug configurations to reduce memory footprint.

Jira: NCSDK-31374

Signed-off-by: Mateusz Kapala <[email protected]>

Author: mkapala-nordic

applications/nrf_desktop/configuration/nrf54h20dk_nrf54h20_cpuapp/prj.conf

@@ -78,7 +78,8 @@ CONFIG_IDLE_STACK_SIZE=512
 CONFIG_HW_STACK_PROTECTION=y
 CONFIG_RESET_ON_FATAL_ERROR=n
 
-CONFIG_SPEED_OPTIMIZATIONS=y
+# Optimize for size to reduce memory footprint.
+CONFIG_SIZE_OPTIMIZATIONS=y
 
 CONFIG_REBOOT=y