regulator: add pbias regulator support

pbias register controls internal power supply to sd card i/o pads
in most OMAPs (OMAP2-5, DRA7).
Control bits for selecting voltage level and
enabling/disabling are in the same PBIAS register.

Signed-off-by: Balaji T K <balajitk@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Mark Brown <broonie@linaro.org>
Tested-by: Florian Vaussard <florian.vaussard@epfl.ch>
Tested-by: Stefan Roese <sr@denx.de>
Signed-off-by: Chris Ball <chris@printf.net>
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 6a79328..58f08d1 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -384,6 +384,15 @@
 	  on the muxing. This is handled automatically in the driver by
 	  reading the mux info from OTP.
 
+config REGULATOR_PBIAS
+	tristate "PBIAS OMAP regulator driver"
+	depends on (ARCH_OMAP || COMPILE_TEST) && MFD_SYSCON
+	help
+	 Say y here to support pbias regulator for mmc1:SD card i/o
+	 on OMAP SoCs.
+	 This driver provides support for OMAP pbias modelled
+	 regulators.
+
 config REGULATOR_PCAP
 	tristate "Motorola PCAP2 regulator driver"
 	depends on EZX_PCAP