leds: qti-flash: Fix indentations and change macros to enum

Fix the indentation of macro definitions, kernel-doc comments
and structure member definitions. While at it, change macro
definitions OTST1_IDX, OTST2_IDX and FLASH_THERMAL_LEVELS
(renaming it to OTST_MAX) to enums as it seems to be appropriate
and makes it more readable.

Change-Id: I2c4b68e274a58c71f935cfbf07b9ba59fba90544
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>