coresight: etm4x: splitting struct etmv4_drvdata

Similar to what was done on etm3x, splitting driver structure
etmv4_drvdata in two.  One half is concerned with the HW
characteristics that are generally static in nature.  The other
half deals with user configuration and will change from one
trace session to another.

No gain/loss of functionality is incurred from this patch.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 54ff892b76c68ea3fa0ba53a0cdc4508b35aee6f)

Author: mathieupoirier