um: remove dependency on undefined CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS

um: remove dependency on undefined CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS

CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS is not defined anywhere.

In the submitted patch set [1], the first patch "um/kconfig: introduce
CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS" was not applied.

Only 2/3 and 3/3 were applied, which are now:

 - 730586ff7fad ("um: Allow static linking for non-glibc implementations")
 - 5e1121cd43d4 ("um: Some fixes to build UML with musl")

Given that nobody has noticed the missing first patch for many years,
it seems it was unnecessary.

[1]: https://lore.kernel.org/lkml/20200719210222.2811-1-ignat@cloudflare.com/

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://patch.msgid.link/20240924113342.32530-1-masahiroy@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>