acpi/acpi.h: Use __packed over __attribute__((packed))

Change-Id: Iabbb637c797a361a2cbc55505002774ff4f774e1
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77526
Reviewed-by: Martin L Roth <gaumless@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/include/acpi/acpi.h b/src/include/acpi/acpi.h
index 7651863..33bd735 100644
--- a/src/include/acpi/acpi.h
+++ b/src/include/acpi/acpi.h
@@ -854,7 +854,7 @@
 	acpi_header_t header;
 	uint32_t devices_offset;
 	uint32_t devices_count;
-} __attribute__((packed)) acpi_dbg2_header_t;
+} __packed acpi_dbg2_header_t;
 
 /* DBG2: Microsoft Debug Port Table 2 device entry */
 typedef struct acpi_dbg2_device {
@@ -870,7 +870,7 @@
 	uint8_t  reserved[2];
 	uint16_t base_address_offset;
 	uint16_t address_size_offset;
-} __attribute__((packed)) acpi_dbg2_device_t;
+} __packed acpi_dbg2_device_t;
 
 /* FADT (Fixed ACPI Description Table) */
 typedef struct acpi_fadt {