perf-tests: add bash into RDEPENDS (v5.12-rc5+)

perf-tests: add bash into RDEPENDS (v5.12-rc5+)

Upstream commit:

   commit 1dc481c0b0cf18d3952d93a73c4ece90dec277f0
   Author: Leo Yan <leo.yan@linaro.org>
   Date:   Sat Mar 20 18:45:54 2021 +0800

       perf test: Change to use bash for daemon test

       When executing the daemon test on Arm64 and x86 with Debian (Buster)
       distro, both skip the test case with the log:

Changes tools/perf/tests/shell/daemon.sh to be explicitly bash
(it was already required, but was just skipped on various
distros).

We add it into our RDEPENDS for perf-tests to fixup 5.12+
builds.

We already have relatively heavy RDEPENDS for perf tests (python3), so
adding bash into the RDEPENDS isn't signifcant even for older perf
builds that use the same recipe.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>