meson: streamline target declaration

store the dependency objects themselves instead of strings
massage the target declarations to remove conditional targets based on which targets are enabled

Author: perigoso

meson_options.txt

@@ -36,15 +36,20 @@ option(
 		'ch579',
 		'efm',
 		'gd32',
+		'gd32_rv',
 		'hc32',
 		'lpc',
 		'mm32',
 		'nrf',
 		'nxp',
 		'puya',
+		'renesas_ra',
+		'renesas_rz',
 		'renesas',
 		'rp',
 		'sam',
+		'stm32f1',
+		'stm32f4',
 		'stm',
 		'ti',
 		'xilinx'