libpayload: Improve compatibility

Define INT_MAX, EOF and make sure size_t is available.

Change-Id: I1b4b717d2545ea8312ec52339300307a5bd68f8a
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Reviewed-on: http://review.coreboot.org/104
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/payloads/libpayload/include/limits.h b/payloads/libpayload/include/limits.h
index be7dde0..2fecf23 100644
--- a/payloads/libpayload/include/limits.h
+++ b/payloads/libpayload/include/limits.h
@@ -41,5 +41,6 @@
 #endif
 
 #define UINT_MAX (unsigned int)0xffffffff
+#define INT_MAX (unsigned int)0x7fffffff
 
 #endif