coresight: Kconfig: remove dependency on arch for ETM4X

The coresight ETMV4 has both arm32 bit and arm64 bit support.
Remove the dependency of architecture in Kconfig.

Change-Id: I5615cfd5fbe572e98096c5b96a1ec5d359ab219f
Signed-off-by: Saranya Chidura <schidura@codeaurora.org>