mxc_ocotp: Do not disable the OCOTP clock after every access

Leave the OCOTP turned on, so that we subsequent access do not fail.

After enabling the thermal driver on a mx6sxsabresd board:

U-Boot 2015.01-rc1-18267-g99d4189-dirty (Nov 24 2014 - 12:59:01)

CPU:   Freescale i.MX6SX rev1.0 at 792 MHz
CPU:   Temperature 48 C
Reset cause: POR
Board: MX6SX SABRE SDB
I2C:   ready
DRAM:  1 GiB
PMIC:  PFUZE100 ID=0x10
MMC:   FSL_SDHC: 0, FSL_SDHC: 1, FSL_SDHC: 2
  00:01.0     - 16c3:abcd - Bridge device
   01:00.0    - 8086:08b1 - Network controller
In:    serial
Out:   serial
Err:   serial
Net:
(hang)

As the thermal driver accesses the ocotp registers, its clock will be disabled
afterwards.

Then when the MAC address is read (also from ocotp registers) it will cause a
hang.

Do not disable the ocotp clock to prevent this problem.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
diff --git a/drivers/misc/mxc_ocotp.c b/drivers/misc/mxc_ocotp.c
index 89737af..d92044e 100644
--- a/drivers/misc/mxc_ocotp.c
+++ b/drivers/misc/mxc_ocotp.c
@@ -81,8 +81,6 @@
 	err = !!(readl(&regs->ctrl) & BM_CTRL_ERROR);
 	clear_error(regs);
 
-	enable_ocotp_clk(0);
-
 	if (err) {
 		printf("mxc_ocotp %s(): Access protect error\n", caller);
 		return -EIO;