soc/sifive/fu540: Makefile: include mtime_init in ramstage

Fix compilation issue
clint.c/mtime.c is needed as well in ramstage due to CR 28372 and 28355

Change-Id: I7c7768744a165b97978bb8f7f95acf7b32ca4aa4
Signed-off-by: Philipp Hug <philipp@hug.cx>
Reviewed-on: https://review.coreboot.org/28551
Tested-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
3 files changed