drivers: GICv3: remove the rtb logs of gic write and read

gic_write/read use write/read_relaxed function which will create
lots of RTB logging. Change the API to no_log version to remove
those RTB logs.

Change-Id: Ide59d8c2753364840f8a2b304ef0c169870c8509
Signed-off-by: Runmin Wang <runminw@codeaurora.org>