Use correct frequency for the sd-spi interface

bootrom/sdboot/kprintf.h

@@ -33,6 +33,9 @@ static inline void kputc(char c)
 	while ((int32_t)(*tx) < 0);
 	*tx = c;
 #endif
+	volatile uint32_t *term = (void *) 0x64003000; // Terminal (32 bit)
+	while ((int32_t)(*term) < 0);
+	*term = c;
 }
 
 extern void kputs(const char *);

bootrom/sdboot/sd.c

@@ -12,7 +12,7 @@
 
 #define PAYLOAD_SIZE	(16 << 11)
 
-#define F_CLK 50000000UL
+#define F_CLK 60000000UL
 
 static volatile uint32_t * const spi = (void *)(SPI_CTRL_ADDR);