staging: make board support depend on OF_IRQ and CLKDEV_LOOKUP

Building allmodconfig for arch/cris currently fails with:

drivers/built-in.o: In function `board_staging_register_clock':
drivers/staging/board/board.c:131: undefined reference to `clk_add_alias'
make: *** [vmlinux] Error 1

The clk_add_alias lives in drivers/clk/clkdev.c and that file
is only compiled for CONFIG_CLKDEV_LOOKUP, so it would seem
we need to add a dependency on that.

Geert also reported seeing this in his build coverage:

There seems to be another missing dependency on OF_IRQ:

drivers/built-in.o: In function `board_staging_gic_fixup_resources':
(.init.text+0x21c2): undefined reference to `irq_create_of_mapping'

so we might as well fix that at the same time since it is
on the same line.

Cc: Magnus Damm <[e-mail]>
Cc: Simon Horman <[e-mail]>
Cc: Geert Uytterhoeven <[e-mail]>
Acked-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: Paul Gortmaker <[e-mail]>
Signed-off-by: Chen Gang <[e-mail]>
Cc: Stephen Rothwell <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/board/Kconfig

···
 config STAGING_BOARD
 	bool "Staging Board Support"
-	depends on OF_ADDRESS
+	depends on OF_ADDRESS && OF_IRQ && CLKDEV_LOOKUP
 	help
 	  Select to enable per-board staging support code.