davinci: fix implicit declaration of function 'davinci_errata_workarounds'

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

board/davinci/common/psc.h

@@ -27,5 +27,6 @@ void dsp_on(void);
 void davinci_enable_uart0(void);
 void davinci_enable_emac(void);
 void davinci_enable_i2c(void);
+void davinci_errata_workarounds(void);
 
 #endif /* __PSC_H */