clk: mvebu: support for 98DX3236 SoC

The 98DX3236, 98DX3336, 98DX4521 and variants have a different TCLK from
the Armada XP (200MHz vs 250MHz). The CPU core clock is fixed at 800MHz.

The clock gating options are a subset of those on the Armada XP.

The core clock divider is different to the Armada XP also.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>