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>

payloads/libpayload/libpci/libpci.c

@@ -82,7 +82,7 @@ void pci_init(struct pci_access *pacc)
 	memset(pacc, 0, sizeof(*pacc));
 }
 
-void pci_cleanup(__attribute__ ((unused)) struct pci_access *pacc)
+void pci_cleanup(__attribute__((unused)) struct pci_access *pacc)
 {
 }