Revert "riscv: cpu: fu740: clear feature disable CSR"

This reverts commit bc8bbb77.

This commit breaks U-Boot booting on SiFive Unleashed board, as
there is no such CSR on U54 core.
Signed-off-by: NBin Meng <bmeng.cn@gmail.com>
Reviewed-by: NLeo Yu-Chi Liang <ycliang@andestech.com>

arch/riscv/cpu/fu540/spl.c

@@ -6,9 +6,6 @@
 
 #include <dm.h>
 #include <log.h>
-#include <asm/csr.h>
-
-#define CSR_U74_FEATURE_DISABLE	0x7c1
 
 int spl_soc_init(void)
 {
@@ -24,15 +21,3 @@ int spl_soc_init(void)
 
 	return 0;
 }
-
-void harts_early_init(void)
-{
-	/*
-	 * Feature Disable CSR
-	 *
-	 * Clear feature disable CSR to '0' to turn on all features for
-	 * each core. This operation must be in M-mode.
-	 */
-	if (CONFIG_IS_ENABLED(RISCV_MMODE))
-		csr_write(CSR_U74_FEATURE_DISABLE, 0);
-}