clk: sunxi-ng: a83t: Fix PLL lock status register offset

The offset for the PLL lock status register was incorrectly set to
0x208, which actually points to an unused register. The correct
register offset is 0x20c.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>