MGS-6622 [#imx-2974] Fix build error using lower version toolchain

Fix following build error using 5.10, 5.4 or lower version toolchain.
5.15 toolchain is OK.

drivers/mxc/gpu-viv/hal/os/linux/kernel/allocator/default/gc_hal_kernel_allocator_gfp.c: In function ‘_GFPAlloc’:
drivers/mxc/gpu-viv/hal/os/linux/kernel/allocator/default/gc_hal_kernel_allocator_gfp.c:568:9: error: a label can only be part of a statement and a declaration is not a statement
568 | void *addr = NULL;

Signed-off-by: Guangliu Ding <guangliu.ding@nxp.com>

drivers/mxc/gpu-viv/hal/os/linux/kernel/allocator/default/gc_hal_kernel_allocator_gfp.c

@@ -554,6 +554,7 @@ _GFPAlloc(
     if (contiguous)
     {
         size_t bytes = NumPages << PAGE_SHIFT;
+        void *addr = NULL;
 
 #if defined(CONFIG_ZONE_DMA32) && LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,37)
         gfp &= ~__GFP_HIGHMEM;
@@ -565,8 +566,6 @@ _GFPAlloc(
 
 Alloc:
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 27)
-        void *addr = NULL;
-
         addr = alloc_pages_exact(bytes, (gfp & ~__GFP_HIGHMEM) | __GFP_NORETRY);
 
         mdlPriv->contiguousPages = addr ? virt_to_page(addr) : gcvNULL;