ARM: tegra: re-calculate the LP1 data for Tegra30/114

This patch re-calculates the LP1 data of tegra30/114_sdram_pad_address
to base on its label not rely on others. This can make easier to
maintain if some other Tegra chips keep re-using these codes in the
future. And change the name of tegra30_sdram_pad_save to
tegra_sdram_pad_save to make it more common to other chips.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>