bsr: add missing MODULE_DESCRIPTION() macro

With ARCH=powerpc, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/char/bsr.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://lore.kernel.org/r/20240615-md-powerpc-drivers-char-v1-1-bff22fd778a4@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>