bcma: drop unneeded check for CONFIG_OF_IRQ

We already have the same check in bcma_of_get_irq which really calls
symbols available with CONFIG_OF_IRQ only. It appears this duplicated
check was accidentally added in commit c58d900c ("bcma: fix building
without OF_IRQ"). The rest of code in bcma_of_fill_device should work
fine without CONFIG_OF_IRQ.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>