board: stm32: switch to DM STM32 timer

Use available DM stm32_timer driver instead of dedicated
mach-stm32/stm32fx/timer.c.

Remove all defines or files previously used for timer usage in
arch/arm/include/asm/arch-stm32fx and in arch/arm/mach-stm32/stm32fx

Enable DM STM32_TIMER for STM32F4/F7 and H7.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/include/configs/stm32h743-eval.h b/include/configs/stm32h743-eval.h
index aa2871d..d6d3547 100644
--- a/include/configs/stm32h743-eval.h
+++ b/include/configs/stm32h743-eval.h
@@ -24,8 +24,7 @@
 
 #define CONFIG_ENV_SIZE			(8 << 10)
 
-#define CONFIG_SYS_ARCH_TIMER
-#define CONFIG_SYS_HZ_CLOCK		250000000
+#define CONFIG_SYS_HZ_CLOCK		1000000
 
 #define CONFIG_CMDLINE_TAG
 #define CONFIG_SETUP_MEMORY_TAGS