As3525 v1/v2 Add power savings menu

Allow user to select cpu undervolt

There have been quite a few issues across the SANSA AMS line related
to CPU undervolting while most players show greatly increased runtime
some crash.
Rather than constanly upping the voltage we now have a
setting with a safe value for all players and the option for lower voltages

I plan to add a few other options here later such as disk
timings and maybe some other clocks/experimental settings

Added: Disk Low speed option for AS3525v2 devices cuts
	frequency to 12 MHz from 24 MHz
Added: Disk Low speed option for AS3525v1 devices cuts
        frequency to 15.5 MHz from 31 MHz

Added: I2c Low Speed AS3525 devices, should be bigger improvement for v1 devices

Fixed: Debug menu for AS3525v2 No SDSLOT frequency,
	Showed IDE freq though it is unused

Added: DBOP and SSP underclocking affects display on v1/v2 respectively

Fixed: debug menu now has SSP frequency, and SSP_CPSR

Update: made settings menu more generic

Update: cleaned up code

Added: Clip v1 & Fuze v1 didn't have HAVE_ADJUSTABLE_CPU_VOLTAGE.
	not sure why but,  waiting on testing to confirm

Added: C200v2 and E200v2 devices and HAVE_ADJUSTABLE_CPU_VOLTAGE.

Fixed: v1 devices don't like display timing set lower (dbop)
       v1 devices don't have a divider set for ssp (causes divide by 0)

Fixed: ClipZip display lags with Max SSP divider changed from 0xFE to 0x32

Fixed: v1 devices didn't work properly with highspeed sd cards
	Added code from http://gerrit.rockbox.org/r/#/c/1704/
	Added powersave and IDE interface enable/disable

Added: V2 devices now have powersave enabled on sd interface

Update: cleaned up code, lang defines, added manual entries

Update ssp clock mechanism added calculated ssp divider to clipzip

Update turn display clock off when clip+ turns off display

Fixed: clipzip wrong register for SSP clock

Change-Id: I04137682243be92f0f8d8bf1cfa54fbb1965559b
TODO: add other players?
23 files changed