sunxi: display: Make lcd display clk phase configurable

sunxi: display: Make lcd display clk phase configurable

While running some tests with an Olinuxino-A13-Micro + a 7" Olimex LCD module
I noticed that the screen flickered. This is caused by the lcd display clk
phase reg value being set to 0, where it should be 1 in this setup.

This commit adds a Kconfig option for the lcd display clk phase, so that we
can set it per board. This defaults to 1, because looking at all the fex
files in sunxi-boards, that is by far the most used value.

This commit updated the Ippo and MSI Primo73 tablet defconfigs to override the
default of 1 with 0, as that is the correct value for those tablets, this
keeps the register settings the same as before this commit.

The Olinuxino-A13 defconfigs are not updated, changing the register setting
for these boards from 0 to 1, this is intentional.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>