powerpc/embedded6xx: Make functions flipper_pic_init() & ug_udbg_putc() static

Change signature of two functions, adding static keyword to prevent the
following two warnings (treated as errors on W=1):

  arch/powerpc/platforms/embedded6xx/flipper-pic.c:135:28: error: no previous prototype for ‘flipper_pic_init’
  arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c:172:6: error: no previous prototype for ‘ug_udbg_putc’
Signed-off-by: NMathieu Malaterre <malat@debian.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/embedded6xx/flipper-pic.c

@@ -132,7 +132,7 @@ static void __flipper_quiesce(void __iomem *io_base)
 	out_be32(io_base + FLIPPER_ICR, 0xffffffff);
 }
 
-struct irq_domain * __init flipper_pic_init(struct device_node *np)
+static struct irq_domain * __init flipper_pic_init(struct device_node *np)
 {
 	struct device_node *pi;
 	struct irq_domain *irq_domain = NULL;

arch/powerpc/platforms/embedded6xx/usbgecko_udbg.c

@@ -169,7 +169,7 @@ static int ug_getc(void)
 /*
  * Transmits a character.
  */
-void ug_udbg_putc(char ch)
+static void ug_udbg_putc(char ch)
 {
 	ug_putc(ch);
 }