rom_load_partition_table() function

Loads the current partition table from flash, if present This method potentially requires similar complexity to the boot path in terms of picking amongst versions, checking signatures etc. As a result it requires a user provided memory buffer as a work area. The work area should byte word-aligned and of sufficient size or BOOTROM_ERROR_INSUFFICIENT_RESOURCES will be returned. The work area size currently required is 3064, so 3K is a good choice. If force_reload is false, then this method will return BOOTROM_OK immediately if the bootrom is loaded, otherwise it will reload the partition table if it has been loaded already, allowing for the partition table to be updated in a running program.