msm_fb: hdmi: change HDMI_PHY_REG1 based on source.

Set value of HDMI_PHY_REG1[2:0] for output voltage swing control.

CRs-Fixed: 488207
Change-Id: I9aeba47491467a14a3141cf7688a95a2f43e80f5
Signed-off-by: Abhishek Kharbanda <akharban@codeaurora.org>