ARM: S5P: Extend MIPI-CSIS platform_data with the PHY control callback

Extend MIPI-CSIS driver's platform data structure with a callback
for D-PHY enable and reset control. Also add a flag indicating
whether the external MIPI-CSI (VDD18_MIPI) power supply should
be managed in the driver through the "vdd" power supply. On some
boards this regulator may be a fixed voltage regulator without
an inhibit function.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>