software/libbase/spisdcard: add USE_SPISDCARD_RECLOCKING define to easily disable reclocking.

litex/soc/software/libbase/spisdcard.c

@@ -21,6 +21,8 @@
 #include <time.h>
 #include <string.h>
 
+#define USE_SPISCARD_RECLOCKING
+
 #ifdef CSR_SPISDCARD_BASE
 // Import prototypes for the functions
 #include <spisdcard.h>
@@ -444,6 +446,7 @@ uint8_t spi_sdcard_readMBR(void)
         return FAILURE;
     }
 
+#ifdef USE_SPISCARD_RECLOCKING
     // Reclock the card
     // Calculate 16MHz as an integer divider from the CONFIG_CLOCK_FREQUENCY
     // Add 1 as will be rounded down
@@ -468,6 +471,7 @@ uint8_t spi_sdcard_readMBR(void)
             return FAILURE;
         }
     }
+#endif
 
     // Read in FAT16 Root Directory
     // Calculate Storage from TOP of MAIN RAM