pci_drivers/cpu_drivers: Fix constructed arrays on x86_64

The __pci_driver and __cpu_driver uses variable length arrays which are
constructed by the linker at build-time.

The linker always place the structs at 16-byte boundary, as per
"System V ABI". That's not a problem on x86, as the struct is exactly
16 Bytes in size. On other platforms, like x86_64 it breaks, because the
default data alignment isn't SysV compatible.

Set -malign-data=abi to make x86_64 gcc use the SysV psABI.
Fixes broken __pci_driver and __cpu_driver on x86_64.

Change-Id: I2491d47ed03dcfd8db110dfb181b2c5281449591
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/30116
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/xcompile/xcompile

@@ -238,7 +238,7 @@ EOF
 # to use i586 instead.
 if [ "${TARCH}" = "x86_64" ]; then
 cat <<EOF
-	GCC_CFLAGS_${TARCH} += -march=nocona
+	GCC_CFLAGS_${TARCH} += -march=nocona -malign-data=abi
 EOF
 fi