lib:sbi_tlb: Increase tlb fifo entry number

When tlb fifo is full, it takes more fails.
This makes lots of lock contention and
consumes much cpu time in sbi.

include/sbi/sbi_tlb.h

@@ -20,7 +20,7 @@
 
 /* clang-format on */
 
-#define SBI_TLB_FIFO_NUM_ENTRIES		8
+#define SBI_TLB_FIFO_NUM_ENTRIES		64
 
 struct sbi_scratch;