ice40: format-python add back non-zero timing for SB_RAM
ice40: format-python add back non-zero timing for SB_RAM

Signed-off-by: Elms <93f558a3452e88ebb2324de5c5f48ac5d4ec1d53@freshred.net>

SymbiFlow/symbiflow-arch-defs,SymbiFlow/symbiflow-arch-defs