polyphone: update SRCREV

Took me a while to understand whats's going on: master was rebased [1-2] which
causes github release revisions point to thin air. New revision was found by
commit message.

[1] https://github.com/davy7125/polyphone/issues/60
[2] https://github.com/davy7125/polyphone/issues/55

Signed-off-by: Andreas Müller <schnitzeltony@gmail.com>

recipes-musicians/polyphone/polyphone_2.0.1.bb

@@ -24,7 +24,7 @@ SRC_URI = " \
     file://polyphone.mime \
     file://0001-align-compiler-switches-constants-for-cross-compilin.patch \
 "
-SRCREV = "9f9720f4fded286f253e85fc708ee9bbba507eb5"
+SRCREV = "e5863e3147599e51563cd93d5f1e4f96384eba9b"
 S = "${WORKDIR}/git/sources"
 
 do_configure_prepend() {