Provisional fix for bug 3508 - Persistent storage support breaks Linux compatibility.
Enables libnvmemmory.so to be built and dynamically linked on Linux and rom boot reports persistent storage image created OK, but ROM then crashes.
/* fdc.c */
#define MAX_FD 2
typedef struct fdctrl_t fdctrl_t;
fdctrl_t *fdctrl_init (qemu_irq irq, int dma_chann, int mem_mapped,
target_phys_addr_t io_base,
BlockDriverState **fds);
fdctrl_t *sun4m_fdctrl_init (qemu_irq irq, target_phys_addr_t io_base,
BlockDriverState **fds, qemu_irq *fdc_tc);
int fdctrl_get_drive_type(fdctrl_t *fdctrl, int drive_num);