usb: pd: qpnp-pdphy: Set nRetryCount based on PD spec rev

PD 3.0 changed nRetryCount to 2 whereas it was 3 on PD 2.0. This
affects how many times a failed TX message will be attempted in
pd_phy_write(). Add a check for the spec rev field of the message
header to determine what value to set for TX_CONTROL_RETRY_COUNT.

Change-Id: I342262e6555734184222e5a97aac03a148bc900b
Signed-off-by: Jack Pham <jackp@codeaurora.org>