Compile loader only once

Callers must pass ELF machine, byte swapping and symbol LSB clearing
information to ELF loader. A.out loader needs page size information, pass
that too as a parameter.

Extract prototypes to a separate file. Move loader.[ch] and elf_ops.h under hw.

Adjust callers. Also use target_phys_addr_t instead of target_ulong for
addresses: loader addresses aren't virtual.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

hw/palm.c

@@ -24,6 +24,7 @@
 #include "boards.h"
 #include "arm-misc.h"
 #include "devices.h"
+#include "loader.h"
 
 static uint32_t static_readb(void *opaque, target_phys_addr_t offset)
 {