[U-Boot] [U-Boot, v2, 2/2] bootcount: add a DM RTC backing store for bootcount

[Philipp Tomsich]

> This implements a driver using a RTC-based backing store for the DM
> bootcount implementation.  The node configuring this feature will be
> compatible with 'u-boot,bootcount-rtc' and the underlying RTC device
> shall be reference through the property 'rtc'. An offset into the RTC
> device's register space can be provided through the 'offset' property.
> 
> Tested on a RK3399-Q7 on a Flamingo carrier board using the SRAM area
> of the carrier board's RV3029 RTC.
> 
> Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> ---
> 
> Changes in v2: None
> 
>  drivers/bootcount/Kconfig  | 20 +++++++++++
>  drivers/bootcount/Makefile |  1 +
>  drivers/bootcount/rtc.c    | 89 ++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 110 insertions(+)
>  create mode 100644 drivers/bootcount/rtc.c
> 

Applied to u-boot-rockchip, thanks!