usb: pd: qpnp-pdphy: Remove trimming

The TX_TRIM_3 register should not need to be written by the
kernel driver, as we should rely on the part to already have
the correct value either hard coded or adjusted by the boot
loader. Being that it is a secure register also implies as much.

Change-Id: I65cd24b26daa53b2169326376771396e882e4c69
Signed-off-by: Jack Pham <jackp@codeaurora.org>