of: silence warnings due to max() usage

pageblock_order can be (at least) an unsigned int or an unsigned long
depending on the kernel config and architecture, so use max_t(unsigned
long ...) when comparing it.

fixes these warnings:

In file included from include/linux/list.h:8:0,
from include/linux/kobject.h:20,
from include/linux/of.h:21,
from drivers/of/of_reserved_mem.c:17:
drivers/of/of_reserved_mem.c: In function ‘__reserved_mem_alloc_size’:
include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast
(void) (&_max1 == &_max2); \
^
include/linux/kernel.h:747:9: note: in definition of macro ‘max’
typeof(y) _max2 = (y); \
^
drivers/of/of_reserved_mem.c:131:48: note: in expansion of macro ‘max’
align = max(align, (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_ord
^
include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast
(void) (&_max1 == &_max2); \
^
include/linux/kernel.h:747:21: note: in definition of macro ‘max’
typeof(y) _max2 = (y); \
^
drivers/of/of_reserved_mem.c:131:48: note: in expansion of macro ‘max’
align = max(align, (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_ord
^

Fixes: 1cc8e3458b51 ("drivers: of: of_reserved_mem: fixup the alignment with CMA setup")
Signed-off-by: Stephen Rothwell <[e-mail]>
Signed-off-by: Rob Herring <[e-mail]>

drivers/of/of_reserved_mem.c

···
 	if (IS_ENABLED(CONFIG_CMA)
 	    && of_flat_dt_is_compatible(node, "shared-dma-pool")
 	    && of_get_flat_dt_prop(node, "reusable", NULL)
-	    && !of_get_flat_dt_prop(node, "no-map", NULL))
-		align = max(align, (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
+	    && !of_get_flat_dt_prop(node, "no-map", NULL)) {
+		unsigned long order =
+			max_t(unsigned long, MAX_ORDER - 1, pageblock_order);
+
+		align = max(align, (phys_addr_t)PAGE_SIZE << order);
+	}
 
 	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
 	if (prop) {