Add support for RAMTRON/FUJITSU MB85RS1MT FRAM

The MB85RS1MT [1] F-RAM part behaves almost identically to other devices
supported by the RAMTRON driver.  This adds the device ID for this part
and accomodates the shorter Manufacturing ID field.

Upstream-Status: Accepted

[1] http://www.taiwanwebinar.com/zh_TW/STATIC/SITE/MB85RS1MT-DS501-00022-2v0-E.PDF

Signed-off-by: Ash Charles <ashcharles@gmail.com>