Change initdram() return type to phys_size_t

This patch changes the return type of initdram() from long int to phys_size_t.
This is required for a couple of reasons: long int limits the amount of dram
to 2GB, and u-boot in general is moving over to phys_size_t to represent the
size of physical memory.  phys_size_t is defined as an unsigned long on almost
all current platforms.

This patch *only* changes the return type of the initdram function (in
include/common.h, as well as in each board's implementation of initdram).  It
does not actually modify the code inside the function on any of the platforms;
platforms which wish to support more than 2GB of DRAM will need to modify
their initdram() function code.

Build tested with MAKEALL for ppc, arm, mips, mips-el. Booted on powerpc
MPC8641HPCN.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>

board/qemu-mips/qemu-mips.c

@@ -26,7 +26,7 @@
 #include <asm/mipsregs.h>
 #include <asm/io.h>
 
-long int initdram(int board_type)
+phys_size_t initdram(int board_type)
 {
 	/* Sdram is setup by assembler code */
 	/* If memory could be changed, we should return the true value here */