arm: am33xx: Fix MPU opp selection

Update MPU frequencies and voltages as per the latest
DM[1] dated: OCT 2011 Revised APRIL 2016, Section 5.4.
Below is the consolidated data:

MPU values for PG 2.0 and later(Package ZCZ and ZCE):

 -------------------------------------------------------
|	|	  ZCZ		|	  ZCE		|
|-------------------------------------------------------|
|	| VDD[V]   | ARM [MHz]	| VDD[V]   | ARM [MHz]  |
|-------|----------|------------|----------|------------|
| NITRO |  1.325   |   1000     |   NA     |    NA      |
|-------|----------|------------|----------|------------|
| TURBO |   1.26   |    800	|   NA     |    NA      |
|-------|----------|------------|----------|------------|
|OPP120 |   1.20   |    720     |   NA     |    NA      |
|-------|----------|------------|----------|------------|
|OPP100 |   1.10   |    600     |   1.10   |    600     |
|-------|----------|------------|----------|------------|
| OPP50 |   0.95   |    300     |   0.95   |    300     |
 -------------------------------------------------------

There is no eFuse blown on PG1.0 Silicons due to which there is
no way to detect the maximum frequencies supported. So default
to OPP100 for which both frequency and voltages are common on both
the packages.

[1] http://www.ti.com/lit/ds/symlink/am3356.pdf



Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>