fsi: core: Switch to ida_alloc/free

ida_simple_get/remove are deprecated, so switch to ida_alloc/free.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20230612195657.245125-11-eajames@linux.ibm.com


Signed-off-by: Joel Stanley <joel@jms.id.au>