loader/u-boot: Use FDT serial info to create uart

* drop my fdt tests
* we have to call fdt parsing code *after* cpu_init (why?)
* pass fdt pointer to all FDT support calls to avoid confusion
  once we get into the kernel land
* look for PL011 compatible uart and use it
* Add some saftey checks to serial putc code to avoid null*
* fdt_node_check_compatible returns 0 on success not 1
* fdt_get_device_reg needs to add the SOC base to the result
* fdt_get_device_reg might need to add the second range cell
  instead of reg?

headers/private/kernel/platform/u-boot/fdt_serial.h

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2012-2015, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ *
+ * Authors
+ *		Alexander von Gluck IV, [email protected]
+ */
+#ifndef __FDT_SERIAL_H
+#define __FDT_SERIAL_H
+
+
+#include <KernelExport.h>
+#include <arch/generic/debug_uart.h>
+
+
+DebugUART * debug_uart_from_fdt(const void *fdt);
+
+
+#endif /*__FDT_SERIAL_H*/

headers/private/kernel/platform/u-boot/fdt_support.h

@@ -13,11 +13,12 @@
 
 
 void dump_fdt(const void *fdt);
-status_t fdt_get_cell_count(int node, int32 &addressCells, int32 &sizeCells);
+status_t fdt_get_cell_count(const void* fdt, int node,
+	int32 &addressCells, int32 &sizeCells);
 
-phys_addr_t fdt_get_device_reg(int node);
-phys_addr_t fdt_get_device_reg_byname(const char* name);
-phys_addr_t fdt_get_device_reg_byalias(const char* alias);
+phys_addr_t fdt_get_device_reg(const void* fdt, int node);
+phys_addr_t fdt_get_device_reg_byname(const void* fdt, const char* name);
+phys_addr_t fdt_get_device_reg_byalias(const void* fdt, const char* alias);
 
 
 #endif /*__FDT_SUPPORT_H*/