libhwc2.1: remove the if defined guard for histogram

When landing the multi channel histogram, we use the if defined guard
to prevent the build breakage due to older kernel. Now all the kernel
prebuilts are merged, the if defined guard can be removed.

Bug: 295990513
Test: build pass
Change-Id: If65f9cee656d9181fbbef5f6bd8ea2bb414d5c5e
Signed-off-by: Leo Chen <yinchiuan@google.com>
4 files changed