ARM: t20/t30: swap host1x and disp1 clock parents

According to mainline clock tables and TRM HOST1X
parent is PLLC, while DISP1 usually uses PLLP as
parent clock.

Tested-by: Andreas Westman Dorcsak <hedmoo@yahoo.com> # ASUS TF T30
Tested-by: Robert Eckelmann <longnoserob@gmail.com> # ASUS TF101 T20
Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # LG P895 T30
Tested-by: Thierry Reding <treding@nvidia.com> # Beaver T30
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Tom <twarren@nvidia.com>