powerpc: fix 8xx and 82xx type-punning warnings with GCC 4.7

C99's strict aliasing rules are insane to use in low-level code such as a
bootloader, but as Wolfgang has rejected -fno-strict-aliasing in the
past, add a union so that 16-bit accesses can be performed.

Compile-tested only.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: Wolfgang Denk <wd@denx.de>
diff --git a/arch/powerpc/cpu/mpc8260/serial_smc.c b/arch/powerpc/cpu/mpc8260/serial_smc.c
index feba1f6..9410e4c 100644
--- a/arch/powerpc/cpu/mpc8260/serial_smc.c
+++ b/arch/powerpc/cpu/mpc8260/serial_smc.c
@@ -105,7 +105,7 @@
 	/* initialize pointers to SMC */
 
 	sp = (smc_t *) &(im->im_smc[SMC_INDEX]);
-	*(ushort *)(&im->im_dprambase[PROFF_SMC_BASE]) = PROFF_SMC;
+	im->im_dprambase16[PROFF_SMC_BASE / sizeof(u16)] = PROFF_SMC;
 	up = (smc_uart_t *)&im->im_dprambase[PROFF_SMC];
 
 	/* Disable transmitter/receiver. */
@@ -331,7 +331,7 @@
 	/* initialize pointers to SMC */
 
 	sp = (smc_t *) &(im->im_smc[KGDB_SMC_INDEX]);
-	*(ushort *)(&im->im_dprambase[KGDB_PROFF_SMC_BASE]) = KGDB_PROFF_SMC;
+	im->im_dprambase16[KGDB_PROFF_SMC_BASE / sizeof(u16)] = KGDB_PROFF_SMC;
 	up = (smc_uart_t *)&im->im_dprambase[KGDB_PROFF_SMC];
 
 	/* Disable transmitter/receiver. */