staging: tidspbridge: Fix atoi to support hexadecimal numbers correctly

For some strange reason, the DSP base image node/object properties
description string stores hexadecimal numbers with a 'h' or 'H' suffix
instead of a '0x' prefix. This causes parsing issue because the
dspbridge atoi() implementation relies on strict_strtoul(), which will
return an error because of the trailing 'h' character.

As the atoi() return value is never checked for an error anyway, replace
strict_strtoul() with simple_strtoul() to ignore the suffix.

This fix gets rid of the following assertion failed messages that were
printed when running the dsp-dummy test application.

drivers/staging/tidspbridge/rmgr/nldr.c, line 1691:
Assertion (segid == MEMINTERNALID || segid == MEMEXTERNALID) failed.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Omar Ramirez Luna <omar.ramirez@ti.com>