bluetooth: Remove test of CONFIG_CLD_LL_CORE for enable_extldo()

Currently the implementation of function enable_extldo() is protected
by both CONFIG_CNSS and CONFIG_CLD_LL_CORE. CONFIG_CLD_LL_CORE is not
required for the underlying call to cnss_get_platform_cap(), so remove
this test to allow the function to work correctly when CONFIG_CNSS is
defined but CONFIG_CLD_LL_CORE is *not* defined.

Change-Id: I7929b8dca00c1706446837d4f5f3f3c371d935b5
CRs-Fixed: 2220076
Signed-off-by: Jeff Johnson <jjohnson@codeaurora.org>