Port Linux's sizes.h

This is a minor change.  Right now we don't need this header in
assembly, and likely won't, so it's simpler to just change the header
than to import const.h and uapi/const.h.

Signed-off-by: Barret Rhoden <brho@cs.berkeley.edu>

kern/include/linux/sizes.h

diff --git a/kern/include/linux/sizes.h b/kern/include/linux/sizes.h
index fbde0bc..81a8d72 100644
--- a/kern/include/linux/sizes.h
+++ b/kern/include/linux/sizes.h
@@ -8,7 +8,7 @@
 #ifndef __LINUX_SIZES_H__
 #define __LINUX_SIZES_H__
 
-#include <linux/const.h>
+//#include <linux/const.h>
 
 #define SZ_1				0x00000001
 #define SZ_2				0x00000002
@@ -46,6 +46,7 @@
 #define SZ_1G				0x40000000
 #define SZ_2G				0x80000000
 
-#define SZ_4G				_AC(0x100000000, ULL)
+//#define SZ_4G				_AC(0x100000000, ULL)
+#define SZ_4G				0x100000000ULL
 
 #endif /* __LINUX_SIZES_H__ */