u-boot

Added PLL variables (dividers mask/shift, lock enable/detect, etc.)
to new pllinfo struct for each Soc/PLL. PLLA/C/D/E/M/P/U/X.

Used pllinfo struct in all clock functions, validated on T210.
Should be equivalent to prior code on T124/114/30/20. Thanks
to Marcel Ziswiler for corrections to the T20/T30 values.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>