Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h
index 2296112..91010e8 100644
--- a/arch/powerpc/include/asm/compat.h
+++ b/arch/powerpc/include/asm/compat.h
@@ -140,7 +140,7 @@
 	unsigned long usp = regs->gpr[1];
 
 	/*
-	 * We cant access below the stack pointer in the 32bit ABI and
+	 * We can't access below the stack pointer in the 32bit ABI and
 	 * can access 288 bytes in the 64bit ABI
 	 */
 	if (!is_32bit_task())