config: Export the "Current" param type from m5.params.

This type was defined, but it was never added to __all__.

Change-Id: I5414829a9562790416f5ceab71af01503d142903
Reviewed-on: https://gem5-review.googlesource.com/5624
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>

src/python/m5/params.py

@@ -2035,7 +2035,7 @@ __all__ = ['Param', 'VectorParam',
            'TcpPort', 'UdpPort', 'EthernetAddr',
            'IpAddress', 'IpNetmask', 'IpWithPort',
            'MemorySize', 'MemorySize32',
-           'Latency', 'Frequency', 'Clock', 'Voltage',
+           'Latency', 'Frequency', 'Clock', 'Voltage', 'Current',
            'NetworkBandwidth', 'MemoryBandwidth',
            'AddrRange',
            'MaxAddr', 'MaxTick', 'AllMemory',