See DM3730,DM275 data sheet (SPRS685B) footnote (6) in Table 4-19
which says that ABB must be switched to FBB mode when using the
OPP1G.

The LOD definition abb_mpu_iva already exists so that we need
to add plumbing for vbb-supply = <&abb_mpu_iva>
and define two voltage vectors for each OPP so that the abb LDO
is also updated by the ti-cpufreq driver.

We also must switch the ti_cpufreq_soc_data to multi_regulator.

Note: reading out the abb reglator voltage to verify that
it does do transitions can be done by

cat /sys/devices/platform/68000000.ocp/483072f0.regulator-abb-mpu/regulator/regulator.*/microvolts

Likewise, read the twl4030 provided VDD voltage by

cat /sys/devices/platform/68000000.ocp/48070000.i2c/i2c-0/0-0048/48070000.i2c:twl@48:regulator-vdd1/regulator/regulator.*/microvolts

Note: to check if the ABB FBB is enabled/disabled, check
registers

PRM_LDO_ABB_CTRL 0x483072F4 bit 3:0 1=bypass 5=FBB
PRM_LDO_ABB_SETUP 0x483072F0 0x00=bypass 0x11=FBB

e.g.

/dev/mem opened.
Memory mapped at address 0xb6fe4000.
Value at address 0x483072F4 (0xb6fe42f4): 0x3205
/dev/mem opened.
Memory mapped at address 0xb6f89000.
Value at address 0x483072F4 (0xb6f892f4): 0x3201

Note: omap34xx and am3517 have/need no comparable LDO
or mechanism.
Suggested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>