Rename __attribute__((packed)) --> __packed

Also unify __attribute__ ((..)) to __attribute__((..)) and
handle ((__packed__)) like ((packed))

Change-Id: Ie60a51c3fa92b5009724a5b7c2932e361bf3490c
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/15921
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

Documentation/cbfs.txt

@@ -152,7 +152,7 @@ struct cbfs_header {
         u32 offset;
         u32 architecture;
         u32 pad[1];
-} __attribute__((packed));
+} __packed;
 
 The meaning of each member is as follows:
 

Documentation/timestamp.md

@@ -65,7 +65,7 @@ After such a transition, timestamp_init() must not be run again.
 Data structures used
 ====================
 The main structure that maintains information about the timestamp cache is:
-struct __attribute__((__packed__)) timestamp_cache {
+struct __packed timestamp_cache {
         uint16_t cache_state;
         struct timestamp_table table;
         struct timestamp_entry entries[MAX_TIMESTAMP_CACHE];
@@ -109,7 +109,7 @@ struct timestamp_table {
         uint32_t        max_entries;
         uint32_t        num_entries;
         struct timestamp_entry entries[0]; /* Variable number of entries */
-} __attribute__((packed));
+} __packed;
 
 It indicates the base time for all timestamp entries, maximum number
 of entries that can be stored, total number of entries that currently
@@ -125,7 +125,7 @@ defined by:
 struct timestamp_entry {
         uint32_t        entry_id;
         uint64_t        entry_stamp;
-} __attribute__((packed));
+} __packed;
 
 entry_id holds the timestamp id corresponding to this entry and
 entry_stamp holds the actual timestamp.