added auxv to elf stack setup

the needed ones for rtdl; AT_NULL, AT_PHDR, AT_ENTRY, AT_PHNUM, AT_PHENT

src/include/kernel/elf.h

@@ -28,6 +28,12 @@
 
 #define STACK_TOP 0x800000000000
 
+#define AT_NULL 0
+#define AT_PHDR 3
+#define AT_PHENT 4
+#define AT_PHNUM 5
+#define AT_ENTRY 9
+
 typedef struct{
 	uint32_t magic;
 	uint8_t bits;