ARM: mach-shmobile: ap4evb, mackerel: fixup scif initialisation for zboot

* Set receive enable and transmit enable bits of SCASCR0 (E6C400089).
  Values previously written to this register was bogus.

  Curiously earlyprintk works with the previous code.

* Remove duplicate initialisation of GPIO port 152, SCIFA0_TXD (0xE6053098).
  This should have no effect other than to very slightly reduce the amount of
  code.
Reported-by: NMagnus Damm <magnus.damm@gmail.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/arm/mach-shmobile/include/mach/head-ap4evb.txt

@@ -87,8 +87,7 @@ WAIT 1, 0xFE40009C
 ED 0xFE400354, 0x01AD8002
 
 LIST "SCIF0 - Serial port for earlyprintk"
-EB 0xE6053098, 0x11
 EB 0xE6053098, 0xe1
 EW 0xE6C40000, 0x0000
 EB 0xE6C40004, 0x19
-EW 0xE6C40008, 0x3000
+EW 0xE6C40008, 0x0030

arch/arm/mach-shmobile/include/mach/head-mackerel.txt

@@ -87,8 +87,7 @@ WAIT 1, 0xFE40009C
 ED 0xFE400354, 0x01AD8002
 
 LIST "SCIF0 - Serial port for earlyprintk"
-EB 0xE6053098, 0x11
 EB 0xE6053098, 0xe1
 EW 0xE6C40000, 0x0000
 EB 0xE6C40004, 0x19
-EW 0xE6C40008, 0x3000
+EW 0xE6C40008, 0x0030