[realtek] Always set high dword of ring address registers

Some RTL8169 cards (observed with an RTL8169SC) power up with garbage
values in the ring address registers, and do not clear the registers
on reset.

Fix by always setting the high dword of the ring address registers.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/realtek.c

 
 	/* Program ring address */
 	address = virt_to_bus ( ring->desc );
+	writel ( ( ( ( uint64_t ) address ) >> 32 ),
+		 rtl->regs + ring->reg + 4 );
 	writel ( ( address & 0xffffffffUL ), rtl->regs + ring->reg );
-	if ( sizeof ( physaddr_t ) > sizeof ( uint32_t ) ) {
-		writel ( ( ( ( uint64_t ) address ) >> 32 ),
-			 rtl->regs + ring->reg + 4 );
-	}
 	DBGC ( rtl, "REALTEK %p ring %02x is at [%08llx,%08llx)\n",
 	       rtl, ring->reg, ( ( unsigned long long ) address ),
 	       ( ( unsigned long long ) address + ring->len ) );