clk: T-Head: Disable on 32-bit Targets

This fails to build on 32-bit targets because of a missing __udivdi3.
IIRC the right way to fix that is to avoid the division, but I just want
a tree that builds and the only real T-Head platforms are 64-bit right
now.

Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20240719151027.16152-1-palmer@rivosinc.com
Acked-by: Drew Fustini <drew@pdp7.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/thead/Kconfig

@@ -3,6 +3,7 @@
 config CLK_THEAD_TH1520_AP
 	bool "T-HEAD TH1520 AP clock support"
 	depends on ARCH_THEAD || COMPILE_TEST
+	depends on 64BIT
 	default ARCH_THEAD
 	select REGMAP_MMIO
 	help