arch: arm: aarch32: Refresh CORTEX_M_DWT in menuconfig

Currently, CORTEX_M_DWT option does not refresh its value when
TIMING_FUNCTIONS, on which it depends, is selected via menuconfig.
This occurs because during the early west build steps the
aarch32-specific Kconfig file is parsed with TIMING_FUNCTIONS=n,
resulting in CORTEX_M_DWT being set to 'n' (not set) in .config.

Later, when the user runs west with -t menuconfig and sets
TIMING_FUNCTIONS=y using the menus or any other option that selects
TIMING_FUNCTIONS=y indirectly, CORTEX_M_DWT is already set to 'n' and
remains set as such. That is inconvenient, and, moreoever, since
CORTEX_M_DWT gets set if TIMING_FUNCTIONS is set in prj.conf, the
current behavior is not consistent, i.e. via the menuconfig setting
TIMING_FUNCTIONS=y doesn't imply selecting CORTEX_M_DWT automatically.

This commit addresses this issue by selecting CORTEX_M_DWT=y if
TIMING_FUNCTIONS becomes set to 'y', otherwise allowing it to be set via
the prompt. This is possible by making the CORTEX_M_DWT prompt
conditional. Hence, in menuconfig, if TIMING_FUNCTIONS gets set
CORTEX_M_DWT is set automatically. If TIMING_FUNCTIONS is not set, a
prompt is presented to allow selecting CORTEX_M_DWT manually.

Signed-off-by: Gustavo Romero <[email protected]>

Author: gromero

arch/arm/core/cortex_m/Kconfig

@@ -379,7 +379,7 @@ config SW_VECTOR_RELAY_CLIENT
 	  initialization.
 
 config CORTEX_M_DWT
-	bool "Data Watchpoint and Trace (DWT)"
+	bool "Data Watchpoint and Trace (DWT)" if !TIMING_FUNCTIONS
 	depends on CPU_CORTEX_M_HAS_DWT
 	default y if TIMING_FUNCTIONS
 	help