INTERNAL: Revert "util: Drop the ENUM_PACKED macro"

This reverts commit 13f7ef5.

Build Error-:
src/gallium/auxiliary/util/u_prim.c:33:4: error: static assertion failed
due to requirement.

size of packed enum was coming 4 instead of 1 due to this change.

Tracked-On: OAM-106853
Signed-off-by: Ankit Agrawal <ankit.agarwal@intel.com>

src/gallium/include/pipe/p_defines.h

@@ -561,7 +561,7 @@ enum pipe_resource_usage {
 /**
  * Primitive types:
  */
-enum PACKED pipe_prim_type {
+enum pipe_prim_type {
  PIPE_PRIM_POINTS,
  PIPE_PRIM_LINES,
  PIPE_PRIM_LINE_LOOP,
@@ -578,7 +578,7 @@ enum PACKED pipe_prim_type {
  PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY,
  PIPE_PRIM_PATCHES,
  PIPE_PRIM_MAX,
-};
+} ENUM_PACKED;
 
 /**
  * Tessellator spacing types

src/util/macros.h

@@ -325,6 +325,14 @@ do { \
 #define ATTRIBUTE_NOINLINE
 #endif
 
+/* Use as: enum name { X, Y } ENUM_PACKED; */
+#if defined(__GNUC__)
+#define ENUM_PACKED __attribute__((packed))
+#else
+#define ENUM_PACKED
+#endif
+
+
 /**
  * Check that STRUCT::FIELD can hold MAXVAL. We use a lot of bitfields
  * in Mesa/gallium. We have to be sure they're of sufficient size to