regulator: ab8500: Remove unused voltage_shift field from struct expand_register

The voltage_shift field of struct expand_register is not used now, remove it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Bengt Jonsson <bengt.g.jonsson@stericsson.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/ab8500.c b/drivers/regulator/ab8500.c
index 279793e..ece31a3 100644
--- a/drivers/regulator/ab8500.c
+++ b/drivers/regulator/ab8500.c
@@ -89,7 +89,6 @@
 		u8 voltage_bank;
 		u8 voltage_reg;
 		u8 voltage_mask;
-		u8 voltage_shift;
 	} expand_register;
 };
 
@@ -1532,7 +1531,6 @@
 			.voltage_bank		= 0x04,
 			.voltage_reg		= 0x01,
 			.voltage_mask		= 0x10,
-			.voltage_shift		= 1,
 		}
 	},
 	[AB8540_LDO_AUX4] = {