VMID driver support is a load time configuration setting.  Thus, change
sysfs attributes to read only.
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20231207224039.35466-2-justintee8345@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>