x86/intel_rdt: Show missing resctrl mount options

In resctrl filesystem, mount options exist to enable L3/L2 CDP and MBA
Software Controller features if the platform supports them:

 mount -t resctrl resctrl [-o cdp[,cdpl2][,mba_MBps]] /sys/fs/resctrl

But currently only "cdp" option is displayed in /proc/mounts. "cdpl2" and
"mba_MBps" options are not shown even when they are active.

Before:
 # mount -t resctrl resctrl -o cdp,mba_MBps /sys/fs/resctrl
 # grep resctrl /proc/mounts
 /sys/fs/resctrl /sys/fs/resctrl resctrl rw,relatime,cdp 0 0

After:
 # mount -t resctrl resctrl -o cdp,mba_MBps /sys/fs/resctrl
 # grep resctrl /proc/mounts
 /sys/fs/resctrl /sys/fs/resctrl resctrl rw,relatime,cdp,mba_MBps 0 0

Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1536796118-60135-1-git-send-email-fenghua.yu@intel.com

arch/x86/kernel/cpu/intel_rdt_rdtgroup.c

@@ -2795,6 +2795,13 @@ static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
 {
 	if (rdt_resources_all[RDT_RESOURCE_L3DATA].alloc_enabled)
 		seq_puts(seq, ",cdp");
+
+	if (rdt_resources_all[RDT_RESOURCE_L2DATA].alloc_enabled)
+		seq_puts(seq, ",cdpl2");
+
+	if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA]))
+		seq_puts(seq, ",mba_MBps");
+
 	return 0;
 }