Build: Enable RAM_FS in all configs on MUSCA B1

Flash on MUSCA B1 is not very stable. It occasionally has some
dirty data which would cause unexpected test failure.
To avoid blocking Open CI, use RAM_FS on MUSCA B1 as workaround.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: I876022ed26ddefc28ad8264cc8a00ca7467f06d8
1 file changed