powerpc/chrp: Make hydra_init() static

Commit 407d418f ("powerpc/chrp: Move PHB discovery") moved the
sole call to hydra_init() to the source file where it is defined, so it
can be made static.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210223095345.2139416-1-geert@linux-m68k.org

arch/powerpc/include/asm/hydra.h

@@ -94,8 +94,6 @@ extern volatile struct Hydra __iomem *Hydra;
 #define HYDRA_INT_EXT7		18	/* Power Off Request */
 #define HYDRA_INT_SPARE		19
 
-extern int hydra_init(void);
-
 #endif /* __KERNEL__ */
 
 #endif /* _ASMPPC_HYDRA_H */

arch/powerpc/platforms/chrp/pci.c

@@ -131,8 +131,7 @@ static struct pci_ops rtas_pci_ops =
 
 volatile struct Hydra __iomem *Hydra = NULL;
 
-int __init
-hydra_init(void)
+static int __init hydra_init(void)
 {
 	struct device_node *np;
 	struct resource r;