python3-pillow-heif: Move to meta-multimedia

Move from meta-python to meta-multimedia which depends on layer
meta-python. This way the recipe will reside in the layer where
its main dependency libheif is.

This work was sponsored by GOVCERT.LU.

Suggested-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Leon Anavi <leon.anavi@konsulko.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>