Reduce warnings/errors in libpayload when using picky compiler options

The new build system uses quite a few more -W flags for the compiler by
default than the old one. And that's for the better.

Change-Id: Ia8e3d28fb35c56760c2bd0983046c7067e8c5dd6
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/72
Tested-by: build bot (Jenkins)
Reviewed-by: Uwe Hermann <uwe@hermann-uwe.de>

payloads/libpayload/arch/i386/coreboot.c

@@ -57,7 +57,7 @@ static void cb_parse_memory(unsigned char *ptr, struct sysinfo_t *info)
 		struct cb_memory_range *range =
 		    (struct cb_memory_range *)MEM_RANGE_PTR(mem, i);
 
-#if MEMMAP_RAM_ONLY
+#ifdef CONFIG_MEMMAP_RAM_ONLY
 		if (range->type != CB_MEM_RAM)
 			continue;
 #endif

payloads/libpayload/arch/i386/main.c

@@ -41,6 +41,7 @@ char *main_argv[MAX_ARGC_COUNT];
  * This is our C entry function - set up the system
  * and jump into the payload entry point.
  */
+void start_main(void);
 void start_main(void)
 {
 	extern int main(int argc, char **argv);

payloads/libpayload/arch/i386/multiboot.c

@@ -45,7 +45,7 @@ static void mb_parse_mmap(struct multiboot_header *table,
 	while(ptr < (start + table->mmap_length)) {
 		struct multiboot_mmap *mmap = (struct multiboot_mmap *) ptr;
 
-#if MEMMAP_RAM_ONLY
+#ifdef CONFIG_MEMMAP_RAM_ONLY
 		/* 1 == normal RAM.  Ignore everything else for now */
 
 		if (mmap->type == 1) {
@@ -56,7 +56,7 @@ static void mb_parse_mmap(struct multiboot_header *table,
 
 			if (++info->n_memranges == SYSINFO_MAX_MEM_RANGES)
 				return;
-#if MEMMAP_RAM_ONLY
+#ifdef CONFIG_MEMMAP_RAM_ONLY
 		}
 #endif
 

payloads/libpayload/arch/i386/virtual.c

@@ -27,6 +27,7 @@
  * SUCH DAMAGE.
  */
 
+#include <unistd.h>
 
 unsigned long virtual_offset = 0;