clk: sunxi-ng: v3s: add the missing PLL_DDR1

The user manual of V3/V3s/S3 declares a PLL_DDR1, however it's forgot
when developing the V3s CCU driver.

Add back the missing PLL_DDR1.

Fixes: d0f11d14 ("clk: sunxi-ng: add support for V3s CCU")
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>