OMAP3: voltage: rename "mpu" voltagedomain to "mpu_iva"

This voltage domain (a.k.a. VDD1) contains both the MPU and the IVA, so
rename appropriately.

Also fixup any users of the "mpu" name to use "mpu_iva"

Signed-off-by: Kevin Hilman <khilman@ti.com>
diff --git a/arch/arm/mach-omap2/omap_twl.c b/arch/arm/mach-omap2/omap_twl.c
index fcd2f62..760487b 100644
--- a/arch/arm/mach-omap2/omap_twl.c
+++ b/arch/arm/mach-omap2/omap_twl.c
@@ -288,7 +288,7 @@
 	if (!twl_sr_enable_autoinit)
 		omap3_twl_set_sr_bit(true);
 
-	voltdm = voltdm_lookup("mpu");
+	voltdm = voltdm_lookup("mpu_iva");
 	omap_voltage_register_pmic(voltdm, &omap3_mpu_volt_info);
 
 	voltdm = voltdm_lookup("core");