Tegra: Move common clock code to arch/arm/cpu/tegra-common/clock.c

This 'commonizes' much of the clock/pll code. SoC-dependent code
and tables are left in arch/cpu/tegraXXX-common/clock.c

Some T30 tables needed whitespace fixes due to checkpatch complaints.

Signed-off-by: Tom Warren <twarren@nvidia.com>