[PATCH v3 2/8] dm: button: add a driver for button driven by gpio

[Simon Glass]

Add a simple driver which allows use of buttons attached to GPIOs.

Reviewed-by: Simon Glass <sjg at chromium.org>
Signed-off-by: Philippe Reynes <philippe.reynes at softathome.com>
---
Changelog:
v3:
- change compatible to gpio-keys and gpio-keys-polled
  (feedback from Neil Armstrong)
v2:
- remove useless default in Kconfig
- re-order include
- fix condition in button_gpio_remove

 drivers/button/Kconfig       |   9 ++++
 drivers/button/Makefile      |   1 +
 drivers/button/button-gpio.c | 112 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 122 insertions(+)
 create mode 100644 drivers/button/button-gpio.c

Applied to u-boot-dm, thanks!