staging: gdm72xx: use print_hex_dump_debug and remove debug macros

Since the kernel already has a function for hex dumps, use that instead
of the driver's own versions. The function supports dynamic debugging,
so also remove some unnecessary debug macros.

Signed-off-by: Kristina Martšenko <kristina.martsenko@gmail.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>