riscv: starfive: Add SYS_CACHE_SHIFT_6 to enable SYS_CACHELINE_SIZE

Some device driver need SYS_CACHELINE_SIZE macro. Add StarFive
SYS_CACHE_SHIFT_6 to enable it.

Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Reviewed-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/arch/riscv/cpu/jh7110/Kconfig b/arch/riscv/cpu/jh7110/Kconfig
index 4d95811..c1d3e6a 100644
--- a/arch/riscv/cpu/jh7110/Kconfig
+++ b/arch/riscv/cpu/jh7110/Kconfig
@@ -13,6 +13,7 @@
 	select SUPPORT_SPL
 	select SPL_RAM if SPL
 	select SPL_STARFIVE_DDR
+	select SYS_CACHE_SHIFT_6
 	select PINCTRL_STARFIVE_JH7110
 	imply MMC
 	imply MMC_BROKEN_CD