The LPC device is not recognized.
Can you try to add your LPC device to the table in flash_enable.c:enables[]
You have to find out the correct device ID since there are several IDs for the LPC device you posted: 0260 MCP51 LPC Bridge 0261 MCP51 LPC Bridge 0262 MCP51 LPC Bridge 0263 MCP51 LPC Bridge
I'd start out using the enable_flash_ck804() function to enable flash access on that system because the flash enable mechanism is often similar across generations of LPC devices from one manufacturer.
Stefan