Convert CONFIG_PHYSMEM to Kconfig

This converts the following to Kconfig:
   CONFIG_PHYSMEM

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Sean Anderson <seanga2@gmail.com>
diff --git a/arch/Kconfig b/arch/Kconfig
index fffddac..3915606 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -195,6 +195,7 @@
 	imply DM_DSA
 	imply CMD_EXTENSION
 	imply KEYBOARD
+	imply PHYSMEM
 
 config SH
 	bool "SuperH architecture"
@@ -246,6 +247,7 @@
 	imply USB_ETHER_SMSC95XX
 	imply USB_HOST_ETHER
 	imply PCH
+	imply PHYSMEM
 	imply RTC_MC146818
 	imply ACPIGEN if !QEMU
 	imply SYSINFO if GENERATE_SMBIOS_TABLE