clk: qcom: gcc-sdmshrike: update usb mock utmi supported frequencies

Add 19.2 MHz support for the gcc_usb30_mp_mock_utmi_clk_src,
gcc_usb30_prim_mock_utmi_clk_src, and
gcc_usb30_sec_mock_utmi_clk_src RCGs.

Change-Id: Id4b0277ca2f7660cd005539a0df80fdac61a48e7
Signed-off-by: David Collins <collinsd@codeaurora.org>