tty: serial: msm: replace iowrite32_rep with writel_relaxed_no_log

RTB logs gets flooded during console write operation due to logged
variant of API. This commit replaces logged variant API with no log
variant to suppress logs.

CRs-Fixed: 1030352
Change-Id: I79f943cbc13553b3dbdce68f5c1143fa54f6eafa
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>