input: touchscreen: bu21150-driver

This driver is for Rohm's touch Analog Front End (AFE) bu21150. It
receives raw frame from touch AFE via SPI so that host processor
can process raw frame to generate touch coordinates.

Change-Id: I6548dbd064e90653c0642e1a40a8834182997c71
Signed-off-by: iuchi <shinya.iuchi.jg@j-display.com>
Git-commit: 7f0911a70b204a2ba90f66b1792b5229b23342eb
Git-repo: https://github.com/JapanDisplayInc/bu21150-driver


[jinglin@codeaurora.org: fix compilation errors on 3.10 kernel, fix bug
in array definition, add commit text]
Signed-off-by: Jing Lin <jinglin@codeaurora.org>