phy: qcom-ufs: remove hard-coded vdda-phy voltage definition

This patch removes the hard-coded voltage number of vdda-phy regulator
and instead, gets it by using the appropriate API.

Change-Id: Iab753c7e94424dd3ccce95296258bba264979cf2
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>