brcmsmac: allocate ucode with GFP_KERNEL

The brcms_ucode_init_buf() duplicates the ucode chunks via kmemdup()
with GFP_ATOMIC as a precondition of wl->lock acquired.  This caused
allocation failures sometimes as reported in the bugzilla below.

When looking at the the real usage, one can find that it's called
solely from brcms_request_fw(), and it's obviously outside the lock.
Hence we can use GFP_KERNEL there safely for avoiding such allocation
errors.

Bugzilla: http://bugzilla.suse.com/show_bug.cgi?id=1085174


Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>