HACK: gfx: pvr: Don't try to complete SGX commands in atomic context

HACK: gfx: pvr: Don't try to complete SGX commands in atomic context

SGXCommandComplete() may be called while holding a spinlock. In such
cases we want to defer the command completion to the MISR. As a quick
non-intrusive hack, add a simple in_atomic() check to
SGXCommandComplete() to make that happen. Obviously this only works
with CONFIG_PREEMPT kernels.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>