small refactoring of TIMER_DIFF (#24678)

A small refactoring of the defines TIMER_DIFF_8, TIMER_DIFF_16, TIMER_DIFF_32, TIMER_DIFF_RAW.
Removing obsolete TIMER_DIFF helper.
Discussion: #24652

platforms/timer.h

@@ -24,10 +24,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <stdint.h>
 
-#define TIMER_DIFF(a, b, max) ((max == UINT8_MAX) ? ((uint8_t)((a) - (b))) : ((max == UINT16_MAX) ? ((uint16_t)((a) - (b))) : ((max == UINT32_MAX) ? ((uint32_t)((a) - (b))) : ((a) >= (b) ? (a) - (b) : (max) + 1 - (b) + (a)))))
-#define TIMER_DIFF_8(a, b) TIMER_DIFF(a, b, UINT8_MAX)
-#define TIMER_DIFF_16(a, b) TIMER_DIFF(a, b, UINT16_MAX)
-#define TIMER_DIFF_32(a, b) TIMER_DIFF(a, b, UINT32_MAX)
+#define TIMER_DIFF_8(a, b) (uint8_t)((a) - (b))
+#define TIMER_DIFF_16(a, b) (uint16_t)((a) - (b))
+#define TIMER_DIFF_32(a, b) (uint32_t)((a) - (b))
 #define TIMER_DIFF_RAW(a, b) TIMER_DIFF_8(a, b)
 
 #ifdef __cplusplus