Camera: Allow a device to request the focus modes at build time

By default, if a HAL supports touch-to-focus, mode selection is
disabled. Make that an option for devices where manual modes
work better without TTF (Macro, for instance)

Change-Id: Id47fba2a9d156b157440485a0fa516871076d9f9
Revert "Camera: fix for non supported camera expoosure setting step from hal is basicily a negitive  value"

This reverts commit 1c49180136c478295f6205401573a62e62945a75.

Negative min value is a valid exposure setting. The patch causes
exposure setting to be always detected as unsupported.