ice: add return value for functions where ICE is disabled

Add proper return value for functions defined when Inline
Crypto Driver is not enabled. This ensures any test case
calling ICE functions to fail gracefully and avoid potential
PCNOC errors.

Tests: 1. Boot sdm660 LA4.0 target with change (FBE enabled)
       2. Run create_key test-> Test fails (expected), no crash observed
       3. Reboot device -> Device booted Successfully
       4. Boot sdm660 LA.4.0 target with change (FDE enabled)
       5. Run create_key test-> Test PASSED, no crash observed
       6. Reboot device -> Device booted Successfully

Change-Id: I35e5c151d5b2860e77c092e6502e25ab1839e567
Signed-off-by: Jiten Patel <jitepate@codeaurora.org>