microblaze: Fix microblaze init vectors

Microblaze vector table stores several vectors (reset, user exception,
interrupt, debug exception and hardware exception).
All these functions can be below address 0x10000. If they are, wrong
vector table is genarated because jump is not setup from two instructions
(imm upper 16bit and brai lower 16bit).
Adding specific offset prevent problem if address is below 0x10000.
For this case only brai instruction is used.
Signed-off-by: NMichal Simek <monstr@monstr.eu>

arch/microblaze/kernel/entry.S

@@ -998,10 +998,13 @@ ENTRY(_reset)
 	/* in current MMU branch you don't care what is here - it is
 	 * used from bootloader site - but this is correct for FS-BOOT */
 	brai	0x70
-	nop
+	.org	0x8
 	brai	TOPHYS(_user_exception); /* syscall handler */
+	.org	0x10
 	brai	TOPHYS(_interrupt);	/* Interrupt handler */
+	.org	0x18
 	brai	TOPHYS(_debug_exception);	/* debug trap handler */
+	.org	0x20
 	brai	TOPHYS(_hw_exception_handler);	/* HW exception handler */
 
 .section .rodata,"a"