memory: omap-gpmc: Add Kconfig option for debug

We support decoding the bootloader values if DEBUG is defined.
But we also need to change the struct omap_hwmod flags to have
HWMOD_INIT_NO_RESET to avoid the GPMC being reset during the
boot. Otherwise just the default timings will be displayed
instead of the bootloader configured timings.

This also allows us to clean up the various GPMC related
hwmod flags. For debugging, we only need HWMOD_INIT_NO_RESET,
and HWMOD_INIT_NO_IDLE is not needed.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>