serial: xuartps: Removed unwanted checks while reading the error conditions

This patch Remove the unwated checks while reading the parity,framing,
overrun and Break detection errors.

Signed-off-by: Nava kishore Manne <navam@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
[stelford@cadence.com: cherry picked from
https://github.com/Xilinx/linux-xlnx commit
b1cf74970df5470ffbc8e7876a9edf5e3498ef94]
Signed-off-by: Scott Telford <stelford@cadence.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>