NTB: epf: allow built-in build

ntb_hw_epf works just as well when built into the kernel image. Don't
force module build.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

Author: baruchsiach

drivers/ntb/hw/epf/Kconfig

@@ -1,6 +1,5 @@
 config NTB_EPF
 	tristate "Generic EPF Non-Transparent Bridge support"
-	depends on m
 	help
 	  This driver supports EPF NTB on configurable endpoint.
 	  If unsure, say N.