mips: bcm63xx: add support for clk_get_parent()

BCM63XX selects HAVE_LEGACY_CLK but does not provide/support
clk_get_parent(), so add a simple implementation of that
function so that callers of it will build without errors.

Fixes these build errors:

mips-linux-ld: drivers/iio/adc/ingenic-adc.o: in function `jz4770_adc_init_clk_div':
ingenic-adc.c:(.text+0xe4): undefined reference to `clk_get_parent'
mips-linux-ld: drivers/iio/adc/ingenic-adc.o: in function `jz4725b_adc_init_clk_div':
ingenic-adc.c:(.text+0x1b8): undefined reference to `clk_get_parent'

Fixes: e7300d0 ("MIPS: BCM63xx: Add support for the Broadcom BCM63xx family of SOCs." )
Signed-off-by: Randy Dunlap <[email protected]>
Reported-by: kernel test robot <[email protected]>
Suggested-by: Russell King (Oracle) <[email protected]>
Cc: Artur Rojek <[email protected]>
Cc: Paul Cercueil <[email protected]>
Cc: [email protected]
Cc: Jonathan Cameron <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Cc: [email protected]
Cc: Florian Fainelli <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Russell King <[email protected]>
Cc: [email protected]
Cc: Jonas Gorski <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Acked-by: Jonathan Cameron <[email protected]>
Acked-by: Russell King (Oracle) <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>

Author: rddunlap

arch/mips/bcm63xx/clk.c

@@ -381,6 +381,12 @@ void clk_disable(struct clk *clk)
 
 EXPORT_SYMBOL(clk_disable);
 
+struct clk *clk_get_parent(struct clk *clk)
+{
+	return NULL;
+}
+EXPORT_SYMBOL(clk_get_parent);
+
 unsigned long clk_get_rate(struct clk *clk)
 {
 	if (!clk)