clk: imx93: Move IMX93_CLK_END macro to clk driver

clk: imx93: Move IMX93_CLK_END macro to clk driver

IMX93_CLK_END was previously defined in imx93-clock.h to indicate
the number of clocks. However, it is not part of the ABI. For starters
it does no really appear in DTS. But what's more important - new clocks
are described later, which contradicts this define in binding header.
So move this macro to clock driver.

Signed-off-by: Pengfei Li <pengfei.li_1@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20241023184651.381265-2-pengfei.li_1@nxp.com
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>