bignum: refactored the hardware abstraction of the mpi peripheral

- `<target>/bignum.c` is replaced by mpi_ll.h ll layer.
- added the mpi hal layer.

components/soc/esp32s2/include/soc/Kconfig.soc_caps.in

@@ -831,6 +831,14 @@ config SOC_SHA_SUPPORT_SHA512_T
     bool
     default y
 
+config SOC_MPI_MEM_BLOCKS_NUM
+    int
+    default 4
+
+config SOC_MPI_OPERATIONS_NUM
+    int
+    default 3
+
 config SOC_RSA_MAX_BIT_LEN
     int
     default 4096

components/soc/esp32s2/include/soc/soc_caps.h

@@ -361,6 +361,10 @@
 #define SOC_SHA_SUPPORT_SHA512_T        (1)
 
 
+/*--------------------------- MPI CAPS ---------------------------------------*/
+#define SOC_MPI_MEM_BLOCKS_NUM (4)
+#define SOC_MPI_OPERATIONS_NUM (3)
+
 /*--------------------------- RSA CAPS ---------------------------------------*/
 #define SOC_RSA_MAX_BIT_LEN    (4096)