drivers: rtc: add ambiq rtc driver

Add Ambiq RTC driver

Signed-off-by: Richard Wheatley <richard.wheatley@ambiq.com>

Author: RichardSWheatley

drivers/rtc/CMakeLists.txt

@@ -9,6 +9,7 @@ zephyr_library_sources(rtc_utils.c)
 
 zephyr_library_sources_ifdef(CONFIG_RTC_RV8263 rtc_rv8263.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_AM1805 rtc_am1805.c)
+zephyr_library_sources_ifdef(CONFIG_RTC_AMBIQ rtc_ambiq.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_DS1307 rtc_ds1307.c)
 zephyr_library_sources_ifdef(CONFIG_USERSPACE rtc_handlers.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_EMUL rtc_emul.c)

drivers/rtc/Kconfig

@@ -42,6 +42,7 @@ config RTC_SHELL
 	  RTC Shell commands
 
 source "drivers/rtc/Kconfig.am1805"
+source "drivers/rtc/Kconfig.ambiq"
 source "drivers/rtc/Kconfig.ds1307"
 source "drivers/rtc/Kconfig.emul"
 source "drivers/rtc/Kconfig.fake"

drivers/rtc/Kconfig.ambiq

@@ -0,0 +1,10 @@
+# Copyright (c) 2024, Ambiq Micro Inc. <www.ambiq.com>
+# SPDX-License-Identifier: Apache-2.0
+
+config RTC_AMBIQ
+	bool "AMBIQ RTC driver"
+	default y
+	depends on DT_HAS_AMBIQ_RTC_ENABLED
+	select AMBIQ_HAL
+	help
+	  Enable the AMBIQ RTC driver.