lib: vsprintf: Add %pa format specifier for phys_addr_t types

Add the %pa format specifier for printing a phys_addr_t
type and its derivative types (such as resource_size_t),
since the physical address size on some platforms can vary
based on build options, regardless of the native integer
type.

Change-Id: I2ba0003d689a9a2bd13f1a1e2d897b6eacc5d224
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>

lib/vsprintf.c

@@ -857,6 +857,7 @@ int kptr_restrict __read_mostly;
  *       correctness of the format string and va_list arguments.
  * - 'K' For a kernel pointer that should be hidden from unprivileged users
  * - 'NF' For a netdev_features_t
+ * - 'a' For a phys_addr_t type and its derivative types (passed by reference)
  *
  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
  * function pointers are really function descriptors, which contain a
@@ -941,6 +942,12 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 			return netdev_feature_string(buf, end, ptr, spec);
 		}
 		break;
+	case 'a':
+		spec.flags |= SPECIAL | SMALL | ZEROPAD;
+		spec.field_width = sizeof(phys_addr_t) * 2 + 2;
+		spec.base = 16;
+		return number(buf, end,
+			      (unsigned long long) *((phys_addr_t *)ptr), spec);
 	}
 	spec.flags |= SMALL;
 	if (spec.field_width == -1) {