clk: sophgo: Fix a warning about void returns value

The cv1800b_clk_setfield function returns void, but was doing "return
writel(...);" and while seemingly having a void function return a void
function is not a warning, when readl is a macro this problem is shown.
Correct the code to instead simply call writel.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Yao Zi <ziyao@disroot.org>

drivers/clk/sophgo/clk-common.h

@@ -70,7 +70,7 @@ cv1800b_clk_setfield(void *base, struct cv1800b_clk_regfield *field, u32 val)
 	u32 new_val = (readl(base + field->offset) & ~mask) |
 		      ((val << field->shift) & mask);
 
-	return writel(new_val, base + field->offset);
+	writel(new_val, base + field->offset);
 }
 
 #endif /* __CLK_SOPHGO_COMMON_H__ */