msm: board-msm7627a-wlan: fix the gpio_set_value_cansleep crash issue

Fix for the crash issue while turn ON/OFF WLAN in case 7627a FFA/Surf
by calling gpio_set_value_cansleep only if the gpio request is successful,
as the GPIO request can be failed due to GPIO expander hardware issue.

Change-Id: If610ad83962d52fcbc05508eb7ad9e9c84a730a8
CRs-Fixed: 365092
Signed-off-by: Santosh Sajjan <ssajjan@codeaurora.org>