arch: arm: replace PLATFORM_SPECIFIC_INIT with PLATFORM_RESET_HOOK

Use generic hook infrastrucutre instead of custom Kconfig and hooks for
ARM.

Replace z_arm_platform_init() with platform_reset().

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

soc/renesas/rcar/rcar_gen3/Kconfig

@@ -7,7 +7,7 @@ config SOC_SERIES_RCAR_GEN3
 config SOC_R8A77951_R7
 	select ARM
 	select CPU_CORTEX_R7
-	select PLATFORM_SPECIFIC_INIT
+	select SOC_RESET_HOOK
 	select CPU_HAS_DCLS
 
 config SOC_R8A77951_A57

soc/renesas/rcar/rcar_gen3/r7/soc.c

@@ -9,7 +9,7 @@
 #include <zephyr/device.h>
 #include <zephyr/sys/barrier.h>
 
-void z_arm_platform_init(void)
+void soc_reset_hook(void)
 {
 	L1C_DisableCaches();
 	L1C_DisableBTAC();

soc/renesas/smartbond/da1469x/Kconfig

@@ -12,6 +12,6 @@ config SOC_SERIES_DA1469X
 	select HAS_PM
 	select CLOCK_CONTROL
 	select CLOCK_CONTROL_SMARTBOND
-	select PLATFORM_SPECIFIC_INIT
+	select SOC_RESET_HOOK
 	select PM_DEVICE if PM
 	imply TIMER_READS_ITS_FREQUENCY_AT_RUNTIME

soc/renesas/smartbond/da1469x/soc.c

@@ -109,7 +109,7 @@ static void z_renesas_configure_cache(void)
 }
 #endif /* CONFIG_HAS_FLASH_LOAD_OFFSET */
 
-void z_arm_platform_init(void)
+void soc_reset_hook(void)
 {
 #if defined(CONFIG_PM)
 	uint32_t *ivt;