- support both voltage register address and command register address
  for each VC channel
- add fields for voltage register address (volra) and command register
  address (cmdra) to struct omap_vc_channel
- use VC/VP register access read/modify/write helper
- remove volra_shift field (use __ffs(mask) for shift value)
- I2C addresses 10-bit, change size to u16
Signed-off-by: NKevin Hilman <khilman@ti.com>

- Add an i2c_slave_address field to the omap_vc_channel
- use VC/VP read/modify/write helper instead of open-coding
- remove smps_sa_shift, use __ffs(mask) for shift value
- I2C addresses 10-bit, change size to u16

Special thanks to Shweta Gulati <shweta.gulati@ti.com> for suggesting
the use of __ffs(x) instead of ffs(x) - 1.
Signed-off-by: NKevin Hilman <khilman@ti.com>

Convert VC/VP register access to use PRM VC/VP accessor functions.  In
the process, move the read/write function pointers from vdd_info into
struct voltagedomain.

No functional changes.

Additional cleanup:
- remove prm_mod field from  VC/VP data structures, the PRM register
  access functions know which PRM module to use.
Signed-off-by: NKevin Hilman <khilman@ti.com>

The VC layer can support PMICs with separate voltage and command
registers by putting the different registers in the PRM_VC_SMPS_VOL_RA
and PRCM_VC_SMPS_CMD_RA registers respectively.

The PMIC data must supply at least a voltage register address
(volt_reg_addr).  The command register address (cmd_reg_addr) is
optional.  If the PMIC data does not supply a separate command
register address, the VC will use the voltage register address for both.
Signed-off-by: NKevin Hilman <khilman@ti.com>

Move the VC instance struct from omap_vdd_info into struct voltagedomain.
While moving, perform some misc. renames for readability.

No functional changes.

Summary of renames:
- rename omap_vc_instance to omap_vc_channel, since there is only
  one instance of the VC IP and this actually represents channels
  using TRM terminology.
- rename 'vc_common' field of VC channel which led to:
  s/vc->vc_common/vc->common/
- remove redundant '_data' suffix
- OMAP3: vc1 --> vc_mpu, vc2 --> vc_core
- omap_vc_bypass_scale_voltage() -> omap_vc_bypass_scale()
Signed-off-by: NKevin Hilman <khilman@ti.com>

merge

As part of the voltage layer cleanup, split out VC specific code into
a dedicated VC layer.  This patch primarily just moves VC code from
voltage.c into vc.c, and adds prototypes to vc.h.

No functional changes.

For readability, each function was given a local 'vc' pointer:

    struct omap_vc_instance_data *vc = voltdm->vdd->vc_data;

and a global replace of s/vdd->vc_data/vc/ was done.

Also vc_init was renamed to vc_init_channel to reflect that this is
per-VC channel initializtion.
Signed-off-by: NKevin Hilman <khilman@ti.com>