cma: Increase the default number of regions

The total number of CMA regions that can be created is statically
decided at compile time via a config option. Incoming memory map
changes increase the number of CMA regions significantly across
almost all targets. Rather than make every target set the CONFIG,
just increase the default number. The additional overhead is very
small.

Change-Id: I2f60ee56b43c256f3bfa4d1e3ab95a8f378568ab
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>

drivers/base/Kconfig

@@ -282,13 +282,13 @@ config CMA_ALIGNMENT
 
 config CMA_AREAS
 	int "Maximum count of the CMA device-private areas"
-	default 7
+	default 15
 	help
 	  CMA allows to create CMA areas for particular devices. This parameter
 	  sets the maximum number of such device private CMA areas in the
 	  system.
 
-	  If unsure, leave the default value "7".
+	  If unsure, leave the default value "15".
 
 config CMA_RESERVE_DEFAULT_AREA
 	bool "Permanently reserve the default area"