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?