nvmem: sunxi_sid: fix A64 SID controller support

nvmem: sunxi_sid: fix A64 SID controller support

Like in H3, A64 SID controller doesn't return correct data
when using direct access. It appears that on A64, SID needs
8 bytes of word_size.

Workaround is to enable read by registers.

Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Tested-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20190818093345.29647-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>