ARM: OMAP: TWL: change the vddmin / vddmax voltages to spec

As vddmin / vddmax voltages for the pmic only describe the pmic
capabilities now, change the voltages to be according to spec.
TWL data manuals give following values:

TWL4030 (SWCS019L) : VDD1: 600mV ... 1450mV, VDD2: 600mV ... 1500mV
TWL5030 (SWCS030E) : VDD1: 600mV ... 1450mV, VDD2: 600mV ... 1500mV
TWL6030 (SWCS045A) : 0V ... 2100mV

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>