Replace __packed with __attribute__((__packed__)) in uapi headers

Linux uapi headers use __packed as an abbreviation for
__attribute__((__packed__)).  In the upstream kernel headers this
is defined in linux/compiler_attributes.h, but it is not defined
in the uapi headers.  Bionic defines it in sys/cdefs.h, which will
almost always provide the needed definition, but there are uapi
headers that use __packed and do not include any system headers
that would include sys/cdefs.h.  Musl's sys/cdefs.h does not
define __packed, which leads to linker errors when __packed is
treated as a variable name.

Replace __packed with __attribute__((__packed__)) when importing
uapi headers to break the dependency on sys/cdefs.h.

Test: m USE_HOST_MUSL=true on oriole-userdebug in internal master
Change-Id: I45f80f4e5aec868b80ce8eb9d757a3e08ae3e1a9
diff --git a/libc/kernel/uapi/sound/sof/fw.h b/libc/kernel/uapi/sound/sof/fw.h
index c36c2b9..97b7de3 100644
--- a/libc/kernel/uapi/sound/sof/fw.h
+++ b/libc/kernel/uapi/sound/sof/fw.h
@@ -46,7 +46,7 @@
   enum snd_sof_fw_blk_type type;
   __u32 size;
   __u32 offset;
-} __packed;
+} __attribute__((__packed__));
 enum snd_sof_fw_mod_type {
   SOF_FW_BASE = 0,
   SOF_FW_MODULE = 1,
@@ -55,11 +55,11 @@
   enum snd_sof_fw_mod_type type;
   __u32 size;
   __u32 num_blocks;
-} __packed;
+} __attribute__((__packed__));
 struct snd_sof_fw_header {
   unsigned char sig[SND_SOF_FW_SIG_SIZE];
   __u32 file_size;
   __u32 num_modules;
   __u32 abi;
-} __packed;
+} __attribute__((__packed__));
 #endif
diff --git a/libc/kernel/uapi/sound/sof/header.h b/libc/kernel/uapi/sound/sof/header.h
index a1a13db..7514550 100644
--- a/libc/kernel/uapi/sound/sof/header.h
+++ b/libc/kernel/uapi/sound/sof/header.h
@@ -26,7 +26,7 @@
   __u32 abi;
   __u32 reserved[4];
   __u32 data[];
-} __packed;
+} __attribute__((__packed__));
 #define SOF_MANIFEST_DATA_TYPE_NHLT 1
 struct sof_manifest_tlv {
   __le32 type;