clk: thead: fix dependency on clk_ignore_unused

clk: thead: fix dependency on clk_ignore_unused

Add the CLK_IGNORE_UNUSED flag to the vp-axi clock (CLK_VP_AXI) to avoid
depending on clk_ignore_unused in the cmdline. Without this fix, the
emmc-sdio clock (CLK_EMMC_SDIO) fails to work after vp-axi is disabled.

Signed-off-by: Drew Fustini <drew@pdp7.com>
Link: https://lore.kernel.org/r/20240731061439.3807172-1-drew@pdp7.com
Fixes: ae81b69fd2b1 ("clk: thead: Add support for T-Head TH1520 AP_SUBSYS clocks")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>