irqchip: Appropriate __init annotation for const data

Init data marked const should be annotated with __initconst for
correctness and not __initdata.  And for those already __initconst,
they should be qualified as const at the compiler level too.
This also fixes LTO builds that otherwise fail with section mismatch
errors.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1507241511551.1806@knanqh.ubzr
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/irqchip/irq-bcm2835.c b/drivers/irqchip/irq-bcm2835.c
index a36ba96..ca35171 100644
--- a/drivers/irqchip/irq-bcm2835.c
+++ b/drivers/irqchip/irq-bcm2835.c
@@ -75,10 +75,10 @@
 #define NR_BANKS		3
 #define IRQS_PER_BANK		32
 
-static int reg_pending[] __initconst = { 0x00, 0x04, 0x08 };
-static int reg_enable[] __initconst = { 0x18, 0x10, 0x14 };
-static int reg_disable[] __initconst = { 0x24, 0x1c, 0x20 };
-static int bank_irqs[] __initconst = { 8, 32, 32 };
+static const int reg_pending[] __initconst = { 0x00, 0x04, 0x08 };
+static const int reg_enable[] __initconst = { 0x18, 0x10, 0x14 };
+static const int reg_disable[] __initconst = { 0x24, 0x1c, 0x20 };
+static const int bank_irqs[] __initconst = { 8, 32, 32 };
 
 static const int shortcuts[] = {
 	7, 9, 10, 18, 19,		/* Bank 1 */