platform: kendryte/k210: Set per-HART stack size to 8KB

All platform except kendryte/k210 use 8KB of per-HART stack hence
this patch set per-HART stack size of kendryte/k210 to 8KB for
consistency.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>

platform/kendryte/k210/platform.h

@@ -12,7 +12,7 @@
 #include <sbi/riscv_io.h>
 
 #define K210_HART_COUNT		2
-#define K210_HART_STACK_SIZE	4096
+#define K210_HART_STACK_SIZE	8192
 
 #define K210_UART_BAUDRATE	115200