HSI: omap_ssi: Remove usage of the deprecated ida_simple_xx() API

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

This is less verbose.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/d72106fc9de28ef8db2ed653febe366d141362a4.1698831563.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>