input: synaptics_i2c_rmi4: add flipx and flipy to sysfs

- modify enable irq function
- fix F$34 issue of interrupt dispatch
- add pressure report
- add sysfs entry flipx/flipy

Change-Id: I648184496639241c45528c6b806b0ae97bc7a555
Git-commit: 3f6a24d9e9af0f5ba229910225637c081255cdc3
Git-repo: git://github.com/synaptics-touch/synaptics-dsx-i2c.git


[amaloche@codeaurora.org: Removed unnecessary parts of patch]
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>