MIPS: BCM63xx: Fix redefinition of clk_* by adding select HAVE_CLK

MIPS: BCM63xx: Fix redefinition of clk_* by adding select HAVE_CLK

arch/mips/bcm63xx/clk.c:249:5: error: redefinition of 'clk_enable'
include/linux/clk.h:295:19: note: previous definition of 'clk_enable' was here
arch/mips/bcm63xx/clk.c:259:6: error: redefinition of 'clk_disable'
include/linux/clk.h:300:20: note: previous definition of 'clk_disable' was here
arch/mips/bcm63xx/clk.c:268:15: error: redefinition of 'clk_get_rate'
include/linux/clk.h:302:29: note: previous definition of 'clk_get_rate' was here
arch/mips/bcm63xx/clk.c:275:13: error: redefinition of 'clk_get'
include/linux/clk.h:281:27: note: previous definition of 'clk_get' was here
arch/mips/bcm63xx/clk.c:302:6: error: redefinition of 'clk_put'
include/linux/clk.h:291:20: note: previous definition of 'clk_put' was here
make[2]: *** [arch/mips/bcm63xx/clk.o] Error 1

Signed-off-by: Yoichi Yuasa <yuasa@linux-mips.org>
Cc: linux-mips@linux-mips.org
Reviewed-by: John Crispin <blogic@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/4141/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>