swiotlb: Declare swiotlb_late_init_with_default_size() in header

Compiler is not happy about one function prototype:

  CC      kernel/dma/swiotlb.o
  kernel/dma/swiotlb.c:275:1: warning: no previous prototype for ‘swiotlb_late_init_with_default_size’ [-Wmissing-prototypes]
  275 | swiotlb_late_init_with_default_size(size_t default_size)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Since it's used outside of the module, move its declaration to the header
from the user.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/x86/pci/sta2x11-fixup.c

@@ -15,7 +15,6 @@
 #include <asm/iommu.h>
 
 #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
-extern int swiotlb_late_init_with_default_size(size_t default_size);
 
 /*
  * We build a list of bus numbers that are under the ConneXt. The

include/linux/swiotlb.h

@@ -34,6 +34,7 @@ int swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
 extern unsigned long swiotlb_nr_tbl(void);
 unsigned long swiotlb_size_or_default(void);
 extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);
+extern int swiotlb_late_init_with_default_size(size_t default_size);
 extern void __init swiotlb_update_mem_attributes(void);
 
 /*