stdint.h header is not fully compatible with C99(ISO9899:1999)

stdint.h provides macros with incorrect type:
  * UINT8_C
  * UINT16_C
  * UINT8_MAX
  * UINT16_MAX

Signed-off-by: Sergey Melnikov <sergey.melnikov@intel.com>
Change-Id: I2d130c782d4485bf6c9e9f068de0bdaa4ba7303f
diff --git a/libc/include/stdint.h b/libc/include/stdint.h
index 293fb03..8e2f99e 100644
--- a/libc/include/stdint.h
+++ b/libc/include/stdint.h
@@ -66,7 +66,7 @@
 #  define INT_FAST8_MIN    INT8_MIN
 #  define INT_FAST8_MAX    INT8_MAX
 
-#  define UINT8_MAX           (255U)
+#  define UINT8_MAX           (255)
 #  define UINT_LEAST8_MAX     UINT8_MAX
 #  define UINT_FAST8_MAX      UINT8_MAX
 #endif
@@ -76,7 +76,7 @@
 #  define INT_LEAST8_C(c)	 INT8_C(c)
 #  define INT_FAST8_C(c)	INT8_C(c)
 
-#  define UINT8_C(c)	c ## U
+#  define UINT8_C(c)	c
 #  define UINT_LEAST8_C(c)  UINT8_C(c)
 #  define UINT_FAST8_C(c)  UINT8_C(c)
 #endif
@@ -99,7 +99,7 @@
 #  define INT_FAST16_MIN	INT32_MIN
 #  define INT_FAST16_MAX	INT32_MAX
 
-#  define UINT16_MAX	(65535U)
+#  define UINT16_MAX	(65535)
 #  define UINT_LEAST16_MAX UINT16_MAX
 #  define UINT_FAST16_MAX UINT32_MAX
 #endif
@@ -109,7 +109,7 @@
 #  define INT_LEAST16_C(c) INT16_C(c)
 #  define INT_FAST16_C(c)	 INT32_C(c)
 
-#  define UINT16_C(c)	c ## U
+#  define UINT16_C(c)	c
 #  define UINT_LEAST16_C(c) UINT16_C(c)
 #  define UINT_FAST16_C(c) UINT32_C(c)
 #endif