msm_fb: HDMI: Support for clock stretching

HDMI Sink may hold off the DDC transaction by stretching the SCL line
during the SCL-low period following the Acknowledge bit as permitted
by the I2C specification. All HDMI Sources shall delay the DDC transaction
while the SCL line is being held low. HDMI_DDC_SETUP register field
<TIME_LIMIT> should be set.

Change-Id: If58ee3f81b5f89ab22c5e74104ba5ad07ff6094d
CRs-Fixed: 296256
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>
Signed-off-by: Ramakrishna Prasad N <crpn@codeaurora.org>