ARM: OMAP: DRA7: hwmod: Make gpmc software supervised as the smart idle is broken

This patch fixes: 'omap_hwmod: gpmc: _wait_target_disable failed'
error during suspend.

This is because smart idle is broken.
Tested in dra7-evm D1 board.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>