AVR: Fix some test options. Skip tests with address-space on Reduced Tiny.

gcc/testsuite/
	* gcc.target/avr/lra-cpymem_qi.c: Remove duplicate -mmcu=.
	* gcc.target/avr/lra-elim.c: Same.
	* gcc.target/avr/pr112830.c: Skip for Reduced Tiny.
	* gcc.target/avr/pr46779-1.c: Same.
	* gcc.target/avr/pr46779-2.c: Same.
	* gcc.target/avr/pr86869.c: Skip for Reduced Tiny and add -std=gnu99
	for GNU-C due to address spaces.
	* gcc.target/avr/pr89270.c: Same.
	* gcc.target/avr/torture/builtins-2-flash.c: Only test address
	space __flash1 if we have it.
	* gcc.target/avr/torture/addr-space-1-1.c: Same.
	* gcc.target/avr/torture/addr-space-2-1.c: Same.