34XX: PM: Workaround to build omap hsmmc as a module

Current omap hsmmc driver is not pm friendly. Build it as a module
because it prevents omap3 retention.
Signed-off-by: Jouni Hogander <jouni.hogander@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/configs/omap_3430sdp_defconfig

@@ -1058,7 +1058,7 @@ CONFIG_MMC_BLOCK_BOUNCE=y
 #
 # MMC/SD Host Controller Drivers
 #
-CONFIG_MMC_OMAP_HS=y
+CONFIG_MMC_OMAP_HS=m
 # CONFIG_MMC_SPI is not set
 # CONFIG_NEW_LEDS is not set
 CONFIG_RTC_LIB=y