mfd: rtsx: Add support for RTL8411B

BugLink: http://bugs.launchpad.net/bugs/1201321

Adding support of model RTL8411B. Since the model is similar to RTL8411,
differences are implemented in rtl8411.c.

Signed-off-by: Roger Tseng <rogerable@realtek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
(cherry picked from commit 9032eabdd3fcfc00aa513a9eef54002cbabb8c9a)
Signed-off-by: Adam Lee <adam.lee@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>