vendorcode/eltan/security: update attribute use

Update the use of __attribute__((weak)) to the preferred __weak

BUG=None
TEST=Builds
BRANCH=None

Change-Id: I75a0e7c03e537be2d38b7f9c6b81eafbb5fb8018
Signed-off-by: Jon Murphy <jpmurphy@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77669
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
diff --git a/src/vendorcode/eltan/security/mboot/mboot.c b/src/vendorcode/eltan/security/mboot/mboot.c
index e8a2f80..cb37140 100644
--- a/src/vendorcode/eltan/security/mboot/mboot.c
+++ b/src/vendorcode/eltan/security/mboot/mboot.c
@@ -271,7 +271,7 @@
  * @retval TPM_E_IOERROR	Unexpected device behavior.
 **/
 
-int __attribute__((weak)) mb_entry(int wake_from_s3)
+__weak int mb_entry(int wake_from_s3)
 {
 	int status;
 
@@ -315,7 +315,7 @@
  * @retval TPM_E_IOERROR	Unexpected device behavior.
  */
 
-int __attribute__((weak))mb_measure(int wake_from_s3)
+__weak int mb_measure(int wake_from_s3)
 {
 	uint32_t status;
 
@@ -357,7 +357,7 @@
  * @retval TPM_SUCCESS		Operation completed successfully.
  * @retval TPM_E_IOERROR	Unexpected device behavior.
  */
-int __attribute__((weak))mb_measure_log_start(void)
+__weak int mb_measure_log_start(void)
 {
 	int status;
 	uint32_t i;
@@ -414,7 +414,7 @@
  * @retval TPM_SUCCESS		Operation completed successfully.
  * @retval TPM_E_IOERROR	Unexpected device behavior.
 **/
-int __attribute__((weak))mb_crtm(void)
+__weak int mb_crtm(void)
 {
 	int status;
 	TCG_PCR_EVENT2_HDR tcgEventHdr;