Resolving issue #700 (moving keep_planar ROM table to under debug switch)

Basic Info

• Related issues: #700 (closed)
• Requested reviewers: @tyagiri

Reason why this change is needed

• In the code foreseen to be delivered (generated via scripts/prepare_delivery.sh --strip_sr), there are a number of unused tables (can be found via scripts/find_unused_symbols.sh):

SHBCB_SubGain5bit_Linear --> nowhere used
keep_planar              --> only used within #ifdef SPAR_HOA_DBG ... #endif
t_design_11_size         --> nowhere used; there is SBA_T_DESIGN_11_SIZE used instead

Description of the change

• Cleanup of the unused tables.

Affected operating points

• BE for bitstream and audio output.