OMAP4: PM: TWL6030: address 0V conversions

0V conversions should be mapped to 0 as it is meant to denote
off voltages.

Signed-off-by: Nishanth Menon <nm@ti.com>
diff --git a/arch/arm/mach-omap2/omap_twl.c b/arch/arm/mach-omap2/omap_twl.c
index 5def7c2..b30adf3 100644
--- a/arch/arm/mach-omap2/omap_twl.c
+++ b/arch/arm/mach-omap2/omap_twl.c
@@ -95,6 +95,8 @@
 		is_offset_valid = true;
 	}
 
+	if (!vsel)
+		return 0;
 	/*
 	 * There is no specific formula for voltage to vsel
 	 * conversion above 1.3V. There are special hardcoded
@@ -127,6 +129,8 @@
 		is_offset_valid = true;
 	}
 
+	if (!uv)
+		return 0x00;
 	/*
 	 * There is no specific formula for voltage to vsel
 	 * conversion above 1.3V. There are special hardcoded