kernel: add missing dependency to KERNEL_RPI_AXIPERF

This symbol is added by the bcm27xx target patches so it should depend
on that target.

Fixes: efd9463d ("kernel: add missing symbol for bcm27xx")
Signed-off-by: NStijn Tintel <stijn@linux-ipv6.be>

config/Config-kernel.in

@@ -84,7 +84,7 @@ config KERNEL_PROFILING
 config KERNEL_RPI_AXIPERF
 	bool "Compile the kernel with RaspberryPi AXI Performance monitors"
 	default y
-	depends on KERNEL_PERF_EVENTS
+	depends on KERNEL_PERF_EVENTS && TARGET_bcm27xx
 
 config KERNEL_UBSAN
 	bool "Compile the kernel with undefined behaviour sanity checker"