staging: rtl8192e: fix kconfig dependency warning for RTLLIB_CRYPTO_WEP

When RTLLIB_CRYPTO_WEP is enabled and CRYPTO is disabled, it results in
the following Kbuild warning:

WARNING: unmet direct dependencies detected for CRYPTO_ARC4
  Depends on [n]: CRYPTO [=n]
  Selected by [m]:
  - RTLLIB_CRYPTO_WEP [=m] && STAGING [=y] && RTLLIB [=m]

The reason is that RTLLIB_CRYPTO_WEP selects CRYPTO_ARC4 without depending
on or selecting CRYPTO while CRYPTO_ARC4 is subordinate to CRYPTO.

Honor the kconfig menu hierarchy to remove kconfig dependency warnings.

Fixes: e0e3dadd ("staging: r8192e: Fix possible error in configuration")
Signed-off-by: Necip Fazil Yildiran <fazilyildiran@gmail.com>
Link: https://lore.kernel.org/r/20200915094209.22664-1-fazilyildiran@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192e/Kconfig

@@ -37,6 +37,7 @@ config RTLLIB_CRYPTO_TKIP
 
 config RTLLIB_CRYPTO_WEP
 	tristate "Support for rtllib WEP crypto"
+	select CRYPTO
 	select CRYPTO_ARC4
 	depends on RTLLIB
 	default y