misc: add Tegra BPMP driver

The Tegra BPMP (Boot and Power Management Processor) is a separate
auxiliary CPU embedded into Tegra to perform power management work, and
controls related features such as clocks, resets, power domains, PMIC I2C
bus, etc. This driver provides the core low-level communication path by
which feature-specific drivers (such as clock) can make requests to the
BPMP. This driver is similar to an MFD driver in the Linux kernel. It is
unconditionally selected by CONFIG_TEGRA186 since virtually any Tegra186
build of U-Boot will need the feature.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 80c1558..4af1cbf 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -121,6 +121,18 @@
 	help
 	  The I2C address of the PCA9551 LED controller.
 
+config TEGRA186_BPMP
+	bool "Enable support for the Tegra186 BPMP driver"
+	depends on TEGRA186
+	help
+	  The Tegra BPMP (Boot and Power Management Processor) is a separate
+	  auxiliary CPU embedded into Tegra to perform power management work,
+	  and controls related features such as clocks, resets, power domains,
+	  PMIC I2C bus, etc. This driver provides the core low-level
+	  communication path by which feature-specific drivers (such as clock)
+	  can make requests to the BPMP. This driver is similar to an MFD
+	  driver in the Linux kernel.
+
 config WINBOND_W83627
 	bool "Enable Winbond Super I/O driver"
 	help