sparc64: Fix prototype warnings for floppy_64.h

Fix the following warnings:

arch/sparc/include/asm/floppy_64.h:200:13: warning: no previous prototype for ‘sparc_floppy_irq’
arch/sparc/include/asm/floppy_64.h:437:6: warning: no previous prototype for ‘sun_pci_fd_dma_callback’

Both sparc_floppy_irq and sun_pci_fd_dma_callback are only used within
arch/sparc/include/asm/floppy_64.h that is included only by
drivers/block/floppy.c, so declare them static.

Link: https://lore.kernel.org/r/20240710094155.458731-2-andreas@gaisler.com
Signed-off-by: Andreas Larsson <andreas@gaisler.com>

Author: andreas-gaisler

arch/sparc/include/asm/floppy_64.h

@@ -197,7 +197,7 @@ static void sun_fd_enable_dma(void)
 	pdma_areasize = pdma_size;
 }
 
-irqreturn_t sparc_floppy_irq(int irq, void *dev_cookie)
+static irqreturn_t sparc_floppy_irq(int irq, void *dev_cookie)
 {
 	if (likely(doing_pdma)) {
 		void __iomem *stat = (void __iomem *) fdc_status;
@@ -434,7 +434,8 @@ static int sun_pci_fd_eject(int drive)
 	return -EINVAL;
 }
 
-void sun_pci_fd_dma_callback(struct ebus_dma_info *p, int event, void *cookie)
+static void sun_pci_fd_dma_callback(struct ebus_dma_info *p, int event,
+				    void *cookie)
 {
 	floppy_interrupt(0, NULL);
 }