memory: brcmstb_dpfe: add separate entry for compile test

Add separate entry for Broadcom STB DPFE driver, enabled by default on
ARCH_BRCMSTB.  This allows compile testing.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index b4533ff..e71cf7b 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -10,7 +10,7 @@
 obj-$(CONFIG_ARM_PL172_MPMC)	+= pl172.o
 obj-$(CONFIG_ATMEL_SDRAMC)	+= atmel-sdramc.o
 obj-$(CONFIG_ATMEL_EBI)		+= atmel-ebi.o
-obj-$(CONFIG_ARCH_BRCMSTB)	+= brcmstb_dpfe.o
+obj-$(CONFIG_BRCMSTB_DPFE)	+= brcmstb_dpfe.o
 obj-$(CONFIG_BT1_L2_CTL)	+= bt1-l2-ctl.o
 obj-$(CONFIG_TI_AEMIF)		+= ti-aemif.o
 obj-$(CONFIG_TI_EMIF)		+= emif.o